mirror of
https://sourceware.org/git/binutils-gdb.git
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4cc98c360d
Commit df22c1e5d5
handled the case that
a separate debug file was passed as the objfile for a shared library
to svr4_fetch_objfile_link_map. However, a separate debug file can
also be passed for TLS variables in the main executable. In addition,
frv_fetch_objfile_link_map also expects to be passed the original
objfile rather than a separate debug file, so pull the code to resolve
a separate debug file to the main objfile up into
target_translate_tls_address.
3196 lines
97 KiB
C
3196 lines
97 KiB
C
/* Handle SVR4 shared libraries for GDB, the GNU Debugger.
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Copyright (C) 1990-2022 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "elf/external.h"
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#include "elf/common.h"
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#include "elf/mips.h"
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#include "symtab.h"
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#include "bfd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "gdbcore.h"
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#include "target.h"
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#include "inferior.h"
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#include "infrun.h"
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#include "regcache.h"
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#include "gdbthread.h"
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#include "observable.h"
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#include "solist.h"
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#include "solib.h"
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#include "solib-svr4.h"
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#include "bfd-target.h"
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#include "elf-bfd.h"
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#include "exec.h"
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#include "auxv.h"
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#include "gdb_bfd.h"
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#include "probe.h"
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static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
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static int svr4_have_link_map_offsets (void);
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static void svr4_relocate_main_executable (void);
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static void svr4_free_library_list (void *p_list);
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static void probes_table_remove_objfile_probes (struct objfile *objfile);
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static void svr4_iterate_over_objfiles_in_search_order (
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struct gdbarch *gdbarch, iterate_over_objfiles_in_search_order_cb_ftype *cb,
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void *cb_data, struct objfile *objfile);
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/* On SVR4 systems, a list of symbols in the dynamic linker where
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GDB can try to place a breakpoint to monitor shared library
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events.
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If none of these symbols are found, or other errors occur, then
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SVR4 systems will fall back to using a symbol as the "startup
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mapping complete" breakpoint address. */
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static const char * const solib_break_names[] =
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{
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"r_debug_state",
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"_r_debug_state",
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"_dl_debug_state",
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"rtld_db_dlactivity",
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"__dl_rtld_db_dlactivity",
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"_rtld_debug_state",
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NULL
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};
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static const char * const bkpt_names[] =
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{
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"_start",
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"__start",
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"main",
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NULL
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};
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static const char * const main_name_list[] =
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{
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"main_$main",
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NULL
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};
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/* What to do when a probe stop occurs. */
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enum probe_action
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{
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/* Something went seriously wrong. Stop using probes and
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revert to using the older interface. */
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PROBES_INTERFACE_FAILED,
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/* No action is required. The shared object list is still
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valid. */
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DO_NOTHING,
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/* The shared object list should be reloaded entirely. */
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FULL_RELOAD,
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/* Attempt to incrementally update the shared object list. If
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the update fails or is not possible, fall back to reloading
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the list in full. */
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UPDATE_OR_RELOAD,
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};
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/* A probe's name and its associated action. */
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struct probe_info
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{
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/* The name of the probe. */
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const char *name;
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/* What to do when a probe stop occurs. */
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enum probe_action action;
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};
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/* A list of named probes and their associated actions. If all
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probes are present in the dynamic linker then the probes-based
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interface will be used. */
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static const struct probe_info probe_info[] =
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{
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{ "init_start", DO_NOTHING },
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{ "init_complete", FULL_RELOAD },
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{ "map_start", DO_NOTHING },
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{ "map_failed", DO_NOTHING },
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{ "reloc_complete", UPDATE_OR_RELOAD },
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{ "unmap_start", DO_NOTHING },
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{ "unmap_complete", FULL_RELOAD },
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};
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#define NUM_PROBES ARRAY_SIZE (probe_info)
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/* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
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the same shared library. */
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static int
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svr4_same_1 (const char *gdb_so_name, const char *inferior_so_name)
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{
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if (strcmp (gdb_so_name, inferior_so_name) == 0)
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return 1;
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/* On Solaris, when starting inferior we think that dynamic linker is
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/usr/lib/ld.so.1, but later on, the table of loaded shared libraries
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contains /lib/ld.so.1. Sometimes one file is a link to another, but
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sometimes they have identical content, but are not linked to each
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other. We don't restrict this check for Solaris, but the chances
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of running into this situation elsewhere are very low. */
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if (strcmp (gdb_so_name, "/usr/lib/ld.so.1") == 0
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&& strcmp (inferior_so_name, "/lib/ld.so.1") == 0)
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return 1;
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/* Similarly, we observed the same issue with amd64 and sparcv9, but with
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different locations. */
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if (strcmp (gdb_so_name, "/usr/lib/amd64/ld.so.1") == 0
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&& strcmp (inferior_so_name, "/lib/amd64/ld.so.1") == 0)
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return 1;
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if (strcmp (gdb_so_name, "/usr/lib/sparcv9/ld.so.1") == 0
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&& strcmp (inferior_so_name, "/lib/sparcv9/ld.so.1") == 0)
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return 1;
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return 0;
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}
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static int
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svr4_same (struct so_list *gdb, struct so_list *inferior)
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{
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return (svr4_same_1 (gdb->so_original_name, inferior->so_original_name));
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}
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static std::unique_ptr<lm_info_svr4>
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lm_info_read (CORE_ADDR lm_addr)
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{
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struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
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std::unique_ptr<lm_info_svr4> lm_info;
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gdb::byte_vector lm (lmo->link_map_size);
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if (target_read_memory (lm_addr, lm.data (), lmo->link_map_size) != 0)
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warning (_("Error reading shared library list entry at %s"),
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paddress (target_gdbarch (), lm_addr));
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else
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{
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struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
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lm_info.reset (new lm_info_svr4);
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lm_info->lm_addr = lm_addr;
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lm_info->l_addr_inferior = extract_typed_address (&lm[lmo->l_addr_offset],
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ptr_type);
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lm_info->l_ld = extract_typed_address (&lm[lmo->l_ld_offset], ptr_type);
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lm_info->l_next = extract_typed_address (&lm[lmo->l_next_offset],
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ptr_type);
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lm_info->l_prev = extract_typed_address (&lm[lmo->l_prev_offset],
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ptr_type);
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lm_info->l_name = extract_typed_address (&lm[lmo->l_name_offset],
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ptr_type);
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}
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return lm_info;
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}
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static int
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has_lm_dynamic_from_link_map (void)
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{
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struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
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return lmo->l_ld_offset >= 0;
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}
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static CORE_ADDR
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lm_addr_check (const struct so_list *so, bfd *abfd)
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{
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lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
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if (!li->l_addr_p)
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{
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struct bfd_section *dyninfo_sect;
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CORE_ADDR l_addr, l_dynaddr, dynaddr;
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l_addr = li->l_addr_inferior;
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if (! abfd || ! has_lm_dynamic_from_link_map ())
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goto set_addr;
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l_dynaddr = li->l_ld;
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dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic");
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if (dyninfo_sect == NULL)
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goto set_addr;
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dynaddr = bfd_section_vma (dyninfo_sect);
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if (dynaddr + l_addr != l_dynaddr)
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{
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CORE_ADDR align = 0x1000;
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CORE_ADDR minpagesize = align;
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if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
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{
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Elf_Internal_Ehdr *ehdr = elf_tdata (abfd)->elf_header;
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Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr;
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int i;
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align = 1;
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for (i = 0; i < ehdr->e_phnum; i++)
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if (phdr[i].p_type == PT_LOAD && phdr[i].p_align > align)
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align = phdr[i].p_align;
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minpagesize = get_elf_backend_data (abfd)->minpagesize;
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}
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/* Turn it into a mask. */
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align--;
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/* If the changes match the alignment requirements, we
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assume we're using a core file that was generated by the
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same binary, just prelinked with a different base offset.
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If it doesn't match, we may have a different binary, the
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same binary with the dynamic table loaded at an unrelated
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location, or anything, really. To avoid regressions,
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don't adjust the base offset in the latter case, although
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odds are that, if things really changed, debugging won't
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quite work.
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One could expect more the condition
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((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
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but the one below is relaxed for PPC. The PPC kernel supports
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either 4k or 64k page sizes. To be prepared for 64k pages,
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PPC ELF files are built using an alignment requirement of 64k.
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However, when running on a kernel supporting 4k pages, the memory
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mapping of the library may not actually happen on a 64k boundary!
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(In the usual case where (l_addr & align) == 0, this check is
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equivalent to the possibly expected check above.)
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Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
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l_addr = l_dynaddr - dynaddr;
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if ((l_addr & (minpagesize - 1)) == 0
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&& (l_addr & align) == ((l_dynaddr - dynaddr) & align))
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{
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if (info_verbose)
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gdb_printf (_("Using PIC (Position Independent Code) "
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"prelink displacement %s for \"%s\".\n"),
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paddress (target_gdbarch (), l_addr),
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so->so_name);
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}
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else
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{
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/* There is no way to verify the library file matches. prelink
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can during prelinking of an unprelinked file (or unprelinking
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of a prelinked file) shift the DYNAMIC segment by arbitrary
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offset without any page size alignment. There is no way to
|
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find out the ELF header and/or Program Headers for a limited
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verification if it they match. One could do a verification
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of the DYNAMIC segment. Still the found address is the best
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one GDB could find. */
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warning (_(".dynamic section for \"%s\" "
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"is not at the expected address "
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"(wrong library or version mismatch?)"), so->so_name);
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}
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}
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set_addr:
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li->l_addr = l_addr;
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li->l_addr_p = 1;
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}
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return li->l_addr;
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}
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/* Per pspace SVR4 specific data. */
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struct svr4_info
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{
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svr4_info () = default;
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~svr4_info ();
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/* Base of dynamic linker structures. */
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CORE_ADDR debug_base = 0;
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/* Validity flag for debug_loader_offset. */
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int debug_loader_offset_p = 0;
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/* Load address for the dynamic linker, inferred. */
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CORE_ADDR debug_loader_offset = 0;
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/* Name of the dynamic linker, valid if debug_loader_offset_p. */
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char *debug_loader_name = nullptr;
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/* Load map address for the main executable. */
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CORE_ADDR main_lm_addr = 0;
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CORE_ADDR interp_text_sect_low = 0;
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CORE_ADDR interp_text_sect_high = 0;
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CORE_ADDR interp_plt_sect_low = 0;
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CORE_ADDR interp_plt_sect_high = 0;
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/* Nonzero if the list of objects was last obtained from the target
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via qXfer:libraries-svr4:read. */
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int using_xfer = 0;
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/* Table of struct probe_and_action instances, used by the
|
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probes-based interface to map breakpoint addresses to probes
|
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and their associated actions. Lookup is performed using
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probe_and_action->prob->address. */
|
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htab_up probes_table;
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/* List of objects loaded into the inferior, used by the probes-
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based interface. */
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struct so_list *solib_list = nullptr;
|
||
};
|
||
|
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/* Per-program-space data key. */
|
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static const struct program_space_key<svr4_info> solib_svr4_pspace_data;
|
||
|
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/* Free the probes table. */
|
||
|
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static void
|
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free_probes_table (struct svr4_info *info)
|
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{
|
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info->probes_table.reset (nullptr);
|
||
}
|
||
|
||
/* Free the solib list. */
|
||
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static void
|
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free_solib_list (struct svr4_info *info)
|
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{
|
||
svr4_free_library_list (&info->solib_list);
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info->solib_list = NULL;
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}
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||
|
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svr4_info::~svr4_info ()
|
||
{
|
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free_solib_list (this);
|
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}
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||
|
||
/* Get the svr4 data for program space PSPACE. If none is found yet, add it now.
|
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This function always returns a valid object. */
|
||
|
||
static struct svr4_info *
|
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get_svr4_info (program_space *pspace)
|
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{
|
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struct svr4_info *info = solib_svr4_pspace_data.get (pspace);
|
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|
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if (info == NULL)
|
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info = solib_svr4_pspace_data.emplace (pspace);
|
||
|
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return info;
|
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}
|
||
|
||
/* Local function prototypes */
|
||
|
||
static int match_main (const char *);
|
||
|
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/* Read program header TYPE from inferior memory. The header is found
|
||
by scanning the OS auxiliary vector.
|
||
|
||
If TYPE == -1, return the program headers instead of the contents of
|
||
one program header.
|
||
|
||
Return vector of bytes holding the program header contents, or an empty
|
||
optional on failure. If successful and P_ARCH_SIZE is non-NULL, the target
|
||
architecture size (32-bit or 64-bit) is returned to *P_ARCH_SIZE. Likewise,
|
||
the base address of the section is returned in *BASE_ADDR. */
|
||
|
||
static gdb::optional<gdb::byte_vector>
|
||
read_program_header (int type, int *p_arch_size, CORE_ADDR *base_addr)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
|
||
CORE_ADDR at_phdr, at_phent, at_phnum, pt_phdr = 0;
|
||
int arch_size, sect_size;
|
||
CORE_ADDR sect_addr;
|
||
int pt_phdr_p = 0;
|
||
|
||
/* Get required auxv elements from target. */
|
||
if (target_auxv_search (current_inferior ()->top_target (),
|
||
AT_PHDR, &at_phdr) <= 0)
|
||
return {};
|
||
if (target_auxv_search (current_inferior ()->top_target (),
|
||
AT_PHENT, &at_phent) <= 0)
|
||
return {};
|
||
if (target_auxv_search (current_inferior ()->top_target (),
|
||
AT_PHNUM, &at_phnum) <= 0)
|
||
return {};
|
||
if (!at_phdr || !at_phnum)
|
||
return {};
|
||
|
||
/* Determine ELF architecture type. */
|
||
if (at_phent == sizeof (Elf32_External_Phdr))
|
||
arch_size = 32;
|
||
else if (at_phent == sizeof (Elf64_External_Phdr))
|
||
arch_size = 64;
|
||
else
|
||
return {};
|
||
|
||
/* Find the requested segment. */
|
||
if (type == -1)
|
||
{
|
||
sect_addr = at_phdr;
|
||
sect_size = at_phent * at_phnum;
|
||
}
|
||
else if (arch_size == 32)
|
||
{
|
||
Elf32_External_Phdr phdr;
|
||
int i;
|
||
|
||
/* Search for requested PHDR. */
|
||
for (i = 0; i < at_phnum; i++)
|
||
{
|
||
int p_type;
|
||
|
||
if (target_read_memory (at_phdr + i * sizeof (phdr),
|
||
(gdb_byte *)&phdr, sizeof (phdr)))
|
||
return {};
|
||
|
||
p_type = extract_unsigned_integer ((gdb_byte *) phdr.p_type,
|
||
4, byte_order);
|
||
|
||
if (p_type == PT_PHDR)
|
||
{
|
||
pt_phdr_p = 1;
|
||
pt_phdr = extract_unsigned_integer ((gdb_byte *) phdr.p_vaddr,
|
||
4, byte_order);
|
||
}
|
||
|
||
if (p_type == type)
|
||
break;
|
||
}
|
||
|
||
if (i == at_phnum)
|
||
return {};
|
||
|
||
/* Retrieve address and size. */
|
||
sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
|
||
4, byte_order);
|
||
sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
|
||
4, byte_order);
|
||
}
|
||
else
|
||
{
|
||
Elf64_External_Phdr phdr;
|
||
int i;
|
||
|
||
/* Search for requested PHDR. */
|
||
for (i = 0; i < at_phnum; i++)
|
||
{
|
||
int p_type;
|
||
|
||
if (target_read_memory (at_phdr + i * sizeof (phdr),
|
||
(gdb_byte *)&phdr, sizeof (phdr)))
|
||
return {};
|
||
|
||
p_type = extract_unsigned_integer ((gdb_byte *) phdr.p_type,
|
||
4, byte_order);
|
||
|
||
if (p_type == PT_PHDR)
|
||
{
|
||
pt_phdr_p = 1;
|
||
pt_phdr = extract_unsigned_integer ((gdb_byte *) phdr.p_vaddr,
|
||
8, byte_order);
|
||
}
|
||
|
||
if (p_type == type)
|
||
break;
|
||
}
|
||
|
||
if (i == at_phnum)
|
||
return {};
|
||
|
||
/* Retrieve address and size. */
|
||
sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr,
|
||
8, byte_order);
|
||
sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz,
|
||
8, byte_order);
|
||
}
|
||
|
||
/* PT_PHDR is optional, but we really need it
|
||
for PIE to make this work in general. */
|
||
|
||
if (pt_phdr_p)
|
||
{
|
||
/* at_phdr is real address in memory. pt_phdr is what pheader says it is.
|
||
Relocation offset is the difference between the two. */
|
||
sect_addr = sect_addr + (at_phdr - pt_phdr);
|
||
}
|
||
|
||
/* Read in requested program header. */
|
||
gdb::byte_vector buf (sect_size);
|
||
if (target_read_memory (sect_addr, buf.data (), sect_size))
|
||
return {};
|
||
|
||
if (p_arch_size)
|
||
*p_arch_size = arch_size;
|
||
if (base_addr)
|
||
*base_addr = sect_addr;
|
||
|
||
return buf;
|
||
}
|
||
|
||
|
||
/* Return program interpreter string. */
|
||
static gdb::optional<gdb::byte_vector>
|
||
find_program_interpreter (void)
|
||
{
|
||
/* If we have a current exec_bfd, use its section table. */
|
||
if (current_program_space->exec_bfd ()
|
||
&& (bfd_get_flavour (current_program_space->exec_bfd ())
|
||
== bfd_target_elf_flavour))
|
||
{
|
||
struct bfd_section *interp_sect;
|
||
|
||
interp_sect = bfd_get_section_by_name (current_program_space->exec_bfd (),
|
||
".interp");
|
||
if (interp_sect != NULL)
|
||
{
|
||
int sect_size = bfd_section_size (interp_sect);
|
||
|
||
gdb::byte_vector buf (sect_size);
|
||
bfd_get_section_contents (current_program_space->exec_bfd (),
|
||
interp_sect, buf.data (), 0, sect_size);
|
||
return buf;
|
||
}
|
||
}
|
||
|
||
/* If we didn't find it, use the target auxiliary vector. */
|
||
return read_program_header (PT_INTERP, NULL, NULL);
|
||
}
|
||
|
||
|
||
/* Scan for DESIRED_DYNTAG in .dynamic section of the target's main executable,
|
||
found by consulting the OS auxillary vector. If DESIRED_DYNTAG is found, 1
|
||
is returned and the corresponding PTR is set. */
|
||
|
||
static int
|
||
scan_dyntag_auxv (const int desired_dyntag, CORE_ADDR *ptr,
|
||
CORE_ADDR *ptr_addr)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
|
||
int arch_size, step;
|
||
long current_dyntag;
|
||
CORE_ADDR dyn_ptr;
|
||
CORE_ADDR base_addr;
|
||
|
||
/* Read in .dynamic section. */
|
||
gdb::optional<gdb::byte_vector> ph_data
|
||
= read_program_header (PT_DYNAMIC, &arch_size, &base_addr);
|
||
if (!ph_data)
|
||
return 0;
|
||
|
||
/* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
|
||
step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
|
||
: sizeof (Elf64_External_Dyn);
|
||
for (gdb_byte *buf = ph_data->data (), *bufend = buf + ph_data->size ();
|
||
buf < bufend; buf += step)
|
||
{
|
||
if (arch_size == 32)
|
||
{
|
||
Elf32_External_Dyn *dynp = (Elf32_External_Dyn *) buf;
|
||
|
||
current_dyntag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
|
||
4, byte_order);
|
||
dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
|
||
4, byte_order);
|
||
}
|
||
else
|
||
{
|
||
Elf64_External_Dyn *dynp = (Elf64_External_Dyn *) buf;
|
||
|
||
current_dyntag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag,
|
||
8, byte_order);
|
||
dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr,
|
||
8, byte_order);
|
||
}
|
||
if (current_dyntag == DT_NULL)
|
||
break;
|
||
|
||
if (current_dyntag == desired_dyntag)
|
||
{
|
||
if (ptr)
|
||
*ptr = dyn_ptr;
|
||
|
||
if (ptr_addr)
|
||
*ptr_addr = base_addr + buf - ph_data->data ();
|
||
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Locate the base address of dynamic linker structs for SVR4 elf
|
||
targets.
|
||
|
||
For SVR4 elf targets the address of the dynamic linker's runtime
|
||
structure is contained within the dynamic info section in the
|
||
executable file. The dynamic section is also mapped into the
|
||
inferior address space. Because the runtime loader fills in the
|
||
real address before starting the inferior, we have to read in the
|
||
dynamic info section from the inferior address space.
|
||
If there are any errors while trying to find the address, we
|
||
silently return 0, otherwise the found address is returned. */
|
||
|
||
static CORE_ADDR
|
||
elf_locate_base (void)
|
||
{
|
||
struct bound_minimal_symbol msymbol;
|
||
CORE_ADDR dyn_ptr, dyn_ptr_addr;
|
||
|
||
/* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
|
||
instead of DT_DEBUG, although they sometimes contain an unused
|
||
DT_DEBUG. */
|
||
if (gdb_bfd_scan_elf_dyntag (DT_MIPS_RLD_MAP,
|
||
current_program_space->exec_bfd (),
|
||
&dyn_ptr, NULL)
|
||
|| scan_dyntag_auxv (DT_MIPS_RLD_MAP, &dyn_ptr, NULL))
|
||
{
|
||
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
|
||
gdb_byte *pbuf;
|
||
int pbuf_size = TYPE_LENGTH (ptr_type);
|
||
|
||
pbuf = (gdb_byte *) alloca (pbuf_size);
|
||
/* DT_MIPS_RLD_MAP contains a pointer to the address
|
||
of the dynamic link structure. */
|
||
if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
|
||
return 0;
|
||
return extract_typed_address (pbuf, ptr_type);
|
||
}
|
||
|
||
/* Then check DT_MIPS_RLD_MAP_REL. MIPS executables now use this form
|
||
because of needing to support PIE. DT_MIPS_RLD_MAP will also exist
|
||
in non-PIE. */
|
||
if (gdb_bfd_scan_elf_dyntag (DT_MIPS_RLD_MAP_REL,
|
||
current_program_space->exec_bfd (),
|
||
&dyn_ptr, &dyn_ptr_addr)
|
||
|| scan_dyntag_auxv (DT_MIPS_RLD_MAP_REL, &dyn_ptr, &dyn_ptr_addr))
|
||
{
|
||
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
|
||
gdb_byte *pbuf;
|
||
int pbuf_size = TYPE_LENGTH (ptr_type);
|
||
|
||
pbuf = (gdb_byte *) alloca (pbuf_size);
|
||
/* DT_MIPS_RLD_MAP_REL contains an offset from the address of the
|
||
DT slot to the address of the dynamic link structure. */
|
||
if (target_read_memory (dyn_ptr + dyn_ptr_addr, pbuf, pbuf_size))
|
||
return 0;
|
||
return extract_typed_address (pbuf, ptr_type);
|
||
}
|
||
|
||
/* Find DT_DEBUG. */
|
||
if (gdb_bfd_scan_elf_dyntag (DT_DEBUG, current_program_space->exec_bfd (),
|
||
&dyn_ptr, NULL)
|
||
|| scan_dyntag_auxv (DT_DEBUG, &dyn_ptr, NULL))
|
||
return dyn_ptr;
|
||
|
||
/* This may be a static executable. Look for the symbol
|
||
conventionally named _r_debug, as a last resort. */
|
||
msymbol = lookup_minimal_symbol ("_r_debug", NULL,
|
||
current_program_space->symfile_object_file);
|
||
if (msymbol.minsym != NULL)
|
||
return BMSYMBOL_VALUE_ADDRESS (msymbol);
|
||
|
||
/* DT_DEBUG entry not found. */
|
||
return 0;
|
||
}
|
||
|
||
/* Locate the base address of dynamic linker structs.
|
||
|
||
For both the SunOS and SVR4 shared library implementations, if the
|
||
inferior executable has been linked dynamically, there is a single
|
||
address somewhere in the inferior's data space which is the key to
|
||
locating all of the dynamic linker's runtime structures. This
|
||
address is the value of the debug base symbol. The job of this
|
||
function is to find and return that address, or to return 0 if there
|
||
is no such address (the executable is statically linked for example).
|
||
|
||
For SunOS, the job is almost trivial, since the dynamic linker and
|
||
all of it's structures are statically linked to the executable at
|
||
link time. Thus the symbol for the address we are looking for has
|
||
already been added to the minimal symbol table for the executable's
|
||
objfile at the time the symbol file's symbols were read, and all we
|
||
have to do is look it up there. Note that we explicitly do NOT want
|
||
to find the copies in the shared library.
|
||
|
||
The SVR4 version is a bit more complicated because the address
|
||
is contained somewhere in the dynamic info section. We have to go
|
||
to a lot more work to discover the address of the debug base symbol.
|
||
Because of this complexity, we cache the value we find and return that
|
||
value on subsequent invocations. Note there is no copy in the
|
||
executable symbol tables. */
|
||
|
||
static CORE_ADDR
|
||
locate_base (struct svr4_info *info)
|
||
{
|
||
/* Check to see if we have a currently valid address, and if so, avoid
|
||
doing all this work again and just return the cached address. If
|
||
we have no cached address, try to locate it in the dynamic info
|
||
section for ELF executables. There's no point in doing any of this
|
||
though if we don't have some link map offsets to work with. */
|
||
|
||
if (info->debug_base == 0 && svr4_have_link_map_offsets ())
|
||
info->debug_base = elf_locate_base ();
|
||
return info->debug_base;
|
||
}
|
||
|
||
/* Find the first element in the inferior's dynamic link map, and
|
||
return its address in the inferior. Return zero if the address
|
||
could not be determined.
|
||
|
||
FIXME: Perhaps we should validate the info somehow, perhaps by
|
||
checking r_version for a known version number, or r_state for
|
||
RT_CONSISTENT. */
|
||
|
||
static CORE_ADDR
|
||
solib_svr4_r_map (struct svr4_info *info)
|
||
{
|
||
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
|
||
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
|
||
CORE_ADDR addr = 0;
|
||
|
||
try
|
||
{
|
||
addr = read_memory_typed_address (info->debug_base + lmo->r_map_offset,
|
||
ptr_type);
|
||
}
|
||
catch (const gdb_exception_error &ex)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
}
|
||
|
||
return addr;
|
||
}
|
||
|
||
/* Find r_brk from the inferior's debug base. */
|
||
|
||
static CORE_ADDR
|
||
solib_svr4_r_brk (struct svr4_info *info)
|
||
{
|
||
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
|
||
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
|
||
|
||
return read_memory_typed_address (info->debug_base + lmo->r_brk_offset,
|
||
ptr_type);
|
||
}
|
||
|
||
/* Find the link map for the dynamic linker (if it is not in the
|
||
normal list of loaded shared objects). */
|
||
|
||
static CORE_ADDR
|
||
solib_svr4_r_ldsomap (struct svr4_info *info)
|
||
{
|
||
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
|
||
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
|
||
enum bfd_endian byte_order = type_byte_order (ptr_type);
|
||
ULONGEST version = 0;
|
||
|
||
try
|
||
{
|
||
/* Check version, and return zero if `struct r_debug' doesn't have
|
||
the r_ldsomap member. */
|
||
version
|
||
= read_memory_unsigned_integer (info->debug_base + lmo->r_version_offset,
|
||
lmo->r_version_size, byte_order);
|
||
}
|
||
catch (const gdb_exception_error &ex)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
}
|
||
|
||
if (version < 2 || lmo->r_ldsomap_offset == -1)
|
||
return 0;
|
||
|
||
return read_memory_typed_address (info->debug_base + lmo->r_ldsomap_offset,
|
||
ptr_type);
|
||
}
|
||
|
||
/* On Solaris systems with some versions of the dynamic linker,
|
||
ld.so's l_name pointer points to the SONAME in the string table
|
||
rather than into writable memory. So that GDB can find shared
|
||
libraries when loading a core file generated by gcore, ensure that
|
||
memory areas containing the l_name string are saved in the core
|
||
file. */
|
||
|
||
static int
|
||
svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
|
||
{
|
||
struct svr4_info *info;
|
||
CORE_ADDR ldsomap;
|
||
CORE_ADDR name_lm;
|
||
|
||
info = get_svr4_info (current_program_space);
|
||
|
||
info->debug_base = 0;
|
||
locate_base (info);
|
||
if (!info->debug_base)
|
||
return 0;
|
||
|
||
ldsomap = solib_svr4_r_ldsomap (info);
|
||
if (!ldsomap)
|
||
return 0;
|
||
|
||
std::unique_ptr<lm_info_svr4> li = lm_info_read (ldsomap);
|
||
name_lm = li != NULL ? li->l_name : 0;
|
||
|
||
return (name_lm >= vaddr && name_lm < vaddr + size);
|
||
}
|
||
|
||
/* See solist.h. */
|
||
|
||
static int
|
||
open_symbol_file_object (int from_tty)
|
||
{
|
||
CORE_ADDR lm, l_name;
|
||
struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
|
||
struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr;
|
||
int l_name_size = TYPE_LENGTH (ptr_type);
|
||
gdb::byte_vector l_name_buf (l_name_size);
|
||
struct svr4_info *info = get_svr4_info (current_program_space);
|
||
symfile_add_flags add_flags = 0;
|
||
|
||
if (from_tty)
|
||
add_flags |= SYMFILE_VERBOSE;
|
||
|
||
if (current_program_space->symfile_object_file)
|
||
if (!query (_("Attempt to reload symbols from process? ")))
|
||
return 0;
|
||
|
||
/* Always locate the debug struct, in case it has moved. */
|
||
info->debug_base = 0;
|
||
if (locate_base (info) == 0)
|
||
return 0; /* failed somehow... */
|
||
|
||
/* First link map member should be the executable. */
|
||
lm = solib_svr4_r_map (info);
|
||
if (lm == 0)
|
||
return 0; /* failed somehow... */
|
||
|
||
/* Read address of name from target memory to GDB. */
|
||
read_memory (lm + lmo->l_name_offset, l_name_buf.data (), l_name_size);
|
||
|
||
/* Convert the address to host format. */
|
||
l_name = extract_typed_address (l_name_buf.data (), ptr_type);
|
||
|
||
if (l_name == 0)
|
||
return 0; /* No filename. */
|
||
|
||
/* Now fetch the filename from target memory. */
|
||
gdb::unique_xmalloc_ptr<char> filename
|
||
= target_read_string (l_name, SO_NAME_MAX_PATH_SIZE - 1);
|
||
|
||
if (filename == nullptr)
|
||
{
|
||
warning (_("failed to read exec filename from attached file"));
|
||
return 0;
|
||
}
|
||
|
||
/* Have a pathname: read the symbol file. */
|
||
symbol_file_add_main (filename.get (), add_flags);
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Data exchange structure for the XML parser as returned by
|
||
svr4_current_sos_via_xfer_libraries. */
|
||
|
||
struct svr4_library_list
|
||
{
|
||
struct so_list *head, **tailp;
|
||
|
||
/* Inferior address of struct link_map used for the main executable. It is
|
||
NULL if not known. */
|
||
CORE_ADDR main_lm;
|
||
};
|
||
|
||
/* This module's 'free_objfile' observer. */
|
||
|
||
static void
|
||
svr4_free_objfile_observer (struct objfile *objfile)
|
||
{
|
||
probes_table_remove_objfile_probes (objfile);
|
||
}
|
||
|
||
/* Implementation for target_so_ops.free_so. */
|
||
|
||
static void
|
||
svr4_free_so (struct so_list *so)
|
||
{
|
||
lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
|
||
|
||
delete li;
|
||
}
|
||
|
||
/* Implement target_so_ops.clear_so. */
|
||
|
||
static void
|
||
svr4_clear_so (struct so_list *so)
|
||
{
|
||
lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
|
||
|
||
if (li != NULL)
|
||
li->l_addr_p = 0;
|
||
}
|
||
|
||
/* Free so_list built so far (called via cleanup). */
|
||
|
||
static void
|
||
svr4_free_library_list (void *p_list)
|
||
{
|
||
struct so_list *list = *(struct so_list **) p_list;
|
||
|
||
while (list != NULL)
|
||
{
|
||
struct so_list *next = list->next;
|
||
|
||
free_so (list);
|
||
list = next;
|
||
}
|
||
}
|
||
|
||
/* Copy library list. */
|
||
|
||
static struct so_list *
|
||
svr4_copy_library_list (struct so_list *src)
|
||
{
|
||
struct so_list *dst = NULL;
|
||
struct so_list **link = &dst;
|
||
|
||
while (src != NULL)
|
||
{
|
||
struct so_list *newobj;
|
||
|
||
newobj = XNEW (struct so_list);
|
||
memcpy (newobj, src, sizeof (struct so_list));
|
||
|
||
lm_info_svr4 *src_li = (lm_info_svr4 *) src->lm_info;
|
||
newobj->lm_info = new lm_info_svr4 (*src_li);
|
||
|
||
newobj->next = NULL;
|
||
*link = newobj;
|
||
link = &newobj->next;
|
||
|
||
src = src->next;
|
||
}
|
||
|
||
return dst;
|
||
}
|
||
|
||
#ifdef HAVE_LIBEXPAT
|
||
|
||
#include "xml-support.h"
|
||
|
||
/* Handle the start of a <library> element. Note: new elements are added
|
||
at the tail of the list, keeping the list in order. */
|
||
|
||
static void
|
||
library_list_start_library (struct gdb_xml_parser *parser,
|
||
const struct gdb_xml_element *element,
|
||
void *user_data,
|
||
std::vector<gdb_xml_value> &attributes)
|
||
{
|
||
struct svr4_library_list *list = (struct svr4_library_list *) user_data;
|
||
const char *name
|
||
= (const char *) xml_find_attribute (attributes, "name")->value.get ();
|
||
ULONGEST *lmp
|
||
= (ULONGEST *) xml_find_attribute (attributes, "lm")->value.get ();
|
||
ULONGEST *l_addrp
|
||
= (ULONGEST *) xml_find_attribute (attributes, "l_addr")->value.get ();
|
||
ULONGEST *l_ldp
|
||
= (ULONGEST *) xml_find_attribute (attributes, "l_ld")->value.get ();
|
||
struct so_list *new_elem;
|
||
|
||
new_elem = XCNEW (struct so_list);
|
||
lm_info_svr4 *li = new lm_info_svr4;
|
||
new_elem->lm_info = li;
|
||
li->lm_addr = *lmp;
|
||
li->l_addr_inferior = *l_addrp;
|
||
li->l_ld = *l_ldp;
|
||
|
||
strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1);
|
||
new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0;
|
||
strcpy (new_elem->so_original_name, new_elem->so_name);
|
||
|
||
*list->tailp = new_elem;
|
||
list->tailp = &new_elem->next;
|
||
}
|
||
|
||
/* Handle the start of a <library-list-svr4> element. */
|
||
|
||
static void
|
||
svr4_library_list_start_list (struct gdb_xml_parser *parser,
|
||
const struct gdb_xml_element *element,
|
||
void *user_data,
|
||
std::vector<gdb_xml_value> &attributes)
|
||
{
|
||
struct svr4_library_list *list = (struct svr4_library_list *) user_data;
|
||
const char *version
|
||
= (const char *) xml_find_attribute (attributes, "version")->value.get ();
|
||
struct gdb_xml_value *main_lm = xml_find_attribute (attributes, "main-lm");
|
||
|
||
if (strcmp (version, "1.0") != 0)
|
||
gdb_xml_error (parser,
|
||
_("SVR4 Library list has unsupported version \"%s\""),
|
||
version);
|
||
|
||
if (main_lm)
|
||
list->main_lm = *(ULONGEST *) main_lm->value.get ();
|
||
}
|
||
|
||
/* The allowed elements and attributes for an XML library list.
|
||
The root element is a <library-list>. */
|
||
|
||
static const struct gdb_xml_attribute svr4_library_attributes[] =
|
||
{
|
||
{ "name", GDB_XML_AF_NONE, NULL, NULL },
|
||
{ "lm", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
|
||
{ "l_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
|
||
{ "l_ld", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
|
||
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
|
||
};
|
||
|
||
static const struct gdb_xml_element svr4_library_list_children[] =
|
||
{
|
||
{
|
||
"library", svr4_library_attributes, NULL,
|
||
GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
|
||
library_list_start_library, NULL
|
||
},
|
||
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
|
||
};
|
||
|
||
static const struct gdb_xml_attribute svr4_library_list_attributes[] =
|
||
{
|
||
{ "version", GDB_XML_AF_NONE, NULL, NULL },
|
||
{ "main-lm", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
|
||
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
|
||
};
|
||
|
||
static const struct gdb_xml_element svr4_library_list_elements[] =
|
||
{
|
||
{ "library-list-svr4", svr4_library_list_attributes, svr4_library_list_children,
|
||
GDB_XML_EF_NONE, svr4_library_list_start_list, NULL },
|
||
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
|
||
};
|
||
|
||
/* Parse qXfer:libraries:read packet into *SO_LIST_RETURN. Return 1 if
|
||
|
||
Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
|
||
case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
|
||
empty, caller is responsible for freeing all its entries. */
|
||
|
||
static int
|
||
svr4_parse_libraries (const char *document, struct svr4_library_list *list)
|
||
{
|
||
auto cleanup = make_scope_exit ([&] ()
|
||
{
|
||
svr4_free_library_list (&list->head);
|
||
});
|
||
|
||
memset (list, 0, sizeof (*list));
|
||
list->tailp = &list->head;
|
||
if (gdb_xml_parse_quick (_("target library list"), "library-list-svr4.dtd",
|
||
svr4_library_list_elements, document, list) == 0)
|
||
{
|
||
/* Parsed successfully, keep the result. */
|
||
cleanup.release ();
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Attempt to get so_list from target via qXfer:libraries-svr4:read packet.
|
||
|
||
Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
|
||
case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
|
||
empty, caller is responsible for freeing all its entries.
|
||
|
||
Note that ANNEX must be NULL if the remote does not explicitly allow
|
||
qXfer:libraries-svr4:read packets with non-empty annexes. Support for
|
||
this can be checked using target_augmented_libraries_svr4_read (). */
|
||
|
||
static int
|
||
svr4_current_sos_via_xfer_libraries (struct svr4_library_list *list,
|
||
const char *annex)
|
||
{
|
||
gdb_assert (annex == NULL || target_augmented_libraries_svr4_read ());
|
||
|
||
/* Fetch the list of shared libraries. */
|
||
gdb::optional<gdb::char_vector> svr4_library_document
|
||
= target_read_stralloc (current_inferior ()->top_target (),
|
||
TARGET_OBJECT_LIBRARIES_SVR4,
|
||
annex);
|
||
if (!svr4_library_document)
|
||
return 0;
|
||
|
||
return svr4_parse_libraries (svr4_library_document->data (), list);
|
||
}
|
||
|
||
#else
|
||
|
||
static int
|
||
svr4_current_sos_via_xfer_libraries (struct svr4_library_list *list,
|
||
const char *annex)
|
||
{
|
||
return 0;
|
||
}
|
||
|
||
#endif
|
||
|
||
/* If no shared library information is available from the dynamic
|
||
linker, build a fallback list from other sources. */
|
||
|
||
static struct so_list *
|
||
svr4_default_sos (svr4_info *info)
|
||
{
|
||
struct so_list *newobj;
|
||
|
||
if (!info->debug_loader_offset_p)
|
||
return NULL;
|
||
|
||
newobj = XCNEW (struct so_list);
|
||
lm_info_svr4 *li = new lm_info_svr4;
|
||
newobj->lm_info = li;
|
||
|
||
/* Nothing will ever check the other fields if we set l_addr_p. */
|
||
li->l_addr = info->debug_loader_offset;
|
||
li->l_addr_p = 1;
|
||
|
||
strncpy (newobj->so_name, info->debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1);
|
||
newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
|
||
strcpy (newobj->so_original_name, newobj->so_name);
|
||
|
||
return newobj;
|
||
}
|
||
|
||
/* Read the whole inferior libraries chain starting at address LM.
|
||
Expect the first entry in the chain's previous entry to be PREV_LM.
|
||
Add the entries to the tail referenced by LINK_PTR_PTR. Ignore the
|
||
first entry if IGNORE_FIRST and set global MAIN_LM_ADDR according
|
||
to it. Returns nonzero upon success. If zero is returned the
|
||
entries stored to LINK_PTR_PTR are still valid although they may
|
||
represent only part of the inferior library list. */
|
||
|
||
static int
|
||
svr4_read_so_list (svr4_info *info, CORE_ADDR lm, CORE_ADDR prev_lm,
|
||
struct so_list ***link_ptr_ptr, int ignore_first)
|
||
{
|
||
CORE_ADDR first_l_name = 0;
|
||
CORE_ADDR next_lm;
|
||
|
||
for (; lm != 0; prev_lm = lm, lm = next_lm)
|
||
{
|
||
so_list_up newobj (XCNEW (struct so_list));
|
||
|
||
lm_info_svr4 *li = lm_info_read (lm).release ();
|
||
newobj->lm_info = li;
|
||
if (li == NULL)
|
||
return 0;
|
||
|
||
next_lm = li->l_next;
|
||
|
||
if (li->l_prev != prev_lm)
|
||
{
|
||
warning (_("Corrupted shared library list: %s != %s"),
|
||
paddress (target_gdbarch (), prev_lm),
|
||
paddress (target_gdbarch (), li->l_prev));
|
||
return 0;
|
||
}
|
||
|
||
/* For SVR4 versions, the first entry in the link map is for the
|
||
inferior executable, so we must ignore it. For some versions of
|
||
SVR4, it has no name. For others (Solaris 2.3 for example), it
|
||
does have a name, so we can no longer use a missing name to
|
||
decide when to ignore it. */
|
||
if (ignore_first && li->l_prev == 0)
|
||
{
|
||
first_l_name = li->l_name;
|
||
info->main_lm_addr = li->lm_addr;
|
||
continue;
|
||
}
|
||
|
||
/* Extract this shared object's name. */
|
||
gdb::unique_xmalloc_ptr<char> buffer
|
||
= target_read_string (li->l_name, SO_NAME_MAX_PATH_SIZE - 1);
|
||
if (buffer == nullptr)
|
||
{
|
||
/* If this entry's l_name address matches that of the
|
||
inferior executable, then this is not a normal shared
|
||
object, but (most likely) a vDSO. In this case, silently
|
||
skip it; otherwise emit a warning. */
|
||
if (first_l_name == 0 || li->l_name != first_l_name)
|
||
warning (_("Can't read pathname for load map."));
|
||
continue;
|
||
}
|
||
|
||
strncpy (newobj->so_name, buffer.get (), SO_NAME_MAX_PATH_SIZE - 1);
|
||
newobj->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
|
||
strcpy (newobj->so_original_name, newobj->so_name);
|
||
|
||
/* If this entry has no name, or its name matches the name
|
||
for the main executable, don't include it in the list. */
|
||
if (! newobj->so_name[0] || match_main (newobj->so_name))
|
||
continue;
|
||
|
||
newobj->next = 0;
|
||
/* Don't free it now. */
|
||
**link_ptr_ptr = newobj.release ();
|
||
*link_ptr_ptr = &(**link_ptr_ptr)->next;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Read the full list of currently loaded shared objects directly
|
||
from the inferior, without referring to any libraries read and
|
||
stored by the probes interface. Handle special cases relating
|
||
to the first elements of the list. */
|
||
|
||
static struct so_list *
|
||
svr4_current_sos_direct (struct svr4_info *info)
|
||
{
|
||
CORE_ADDR lm;
|
||
struct so_list *head = NULL;
|
||
struct so_list **link_ptr = &head;
|
||
int ignore_first;
|
||
struct svr4_library_list library_list;
|
||
|
||
/* Fall back to manual examination of the target if the packet is not
|
||
supported or gdbserver failed to find DT_DEBUG. gdb.server/solib-list.exp
|
||
tests a case where gdbserver cannot find the shared libraries list while
|
||
GDB itself is able to find it via SYMFILE_OBJFILE.
|
||
|
||
Unfortunately statically linked inferiors will also fall back through this
|
||
suboptimal code path. */
|
||
|
||
info->using_xfer = svr4_current_sos_via_xfer_libraries (&library_list,
|
||
NULL);
|
||
if (info->using_xfer)
|
||
{
|
||
if (library_list.main_lm)
|
||
info->main_lm_addr = library_list.main_lm;
|
||
|
||
return library_list.head ? library_list.head : svr4_default_sos (info);
|
||
}
|
||
|
||
/* Always locate the debug struct, in case it has moved. */
|
||
info->debug_base = 0;
|
||
locate_base (info);
|
||
|
||
/* If we can't find the dynamic linker's base structure, this
|
||
must not be a dynamically linked executable. Hmm. */
|
||
if (! info->debug_base)
|
||
return svr4_default_sos (info);
|
||
|
||
/* Assume that everything is a library if the dynamic loader was loaded
|
||
late by a static executable. */
|
||
if (current_program_space->exec_bfd ()
|
||
&& bfd_get_section_by_name (current_program_space->exec_bfd (),
|
||
".dynamic") == NULL)
|
||
ignore_first = 0;
|
||
else
|
||
ignore_first = 1;
|
||
|
||
auto cleanup = make_scope_exit ([&] ()
|
||
{
|
||
svr4_free_library_list (&head);
|
||
});
|
||
|
||
/* Walk the inferior's link map list, and build our list of
|
||
`struct so_list' nodes. */
|
||
lm = solib_svr4_r_map (info);
|
||
if (lm)
|
||
svr4_read_so_list (info, lm, 0, &link_ptr, ignore_first);
|
||
|
||
/* On Solaris, the dynamic linker is not in the normal list of
|
||
shared objects, so make sure we pick it up too. Having
|
||
symbol information for the dynamic linker is quite crucial
|
||
for skipping dynamic linker resolver code. */
|
||
lm = solib_svr4_r_ldsomap (info);
|
||
if (lm)
|
||
svr4_read_so_list (info, lm, 0, &link_ptr, 0);
|
||
|
||
cleanup.release ();
|
||
|
||
if (head == NULL)
|
||
return svr4_default_sos (info);
|
||
|
||
return head;
|
||
}
|
||
|
||
/* Implement the main part of the "current_sos" target_so_ops
|
||
method. */
|
||
|
||
static struct so_list *
|
||
svr4_current_sos_1 (svr4_info *info)
|
||
{
|
||
/* If the solib list has been read and stored by the probes
|
||
interface then we return a copy of the stored list. */
|
||
if (info->solib_list != NULL)
|
||
return svr4_copy_library_list (info->solib_list);
|
||
|
||
/* Otherwise obtain the solib list directly from the inferior. */
|
||
return svr4_current_sos_direct (info);
|
||
}
|
||
|
||
/* Implement the "current_sos" target_so_ops method. */
|
||
|
||
static struct so_list *
|
||
svr4_current_sos (void)
|
||
{
|
||
svr4_info *info = get_svr4_info (current_program_space);
|
||
struct so_list *so_head = svr4_current_sos_1 (info);
|
||
struct mem_range vsyscall_range;
|
||
|
||
/* Filter out the vDSO module, if present. Its symbol file would
|
||
not be found on disk. The vDSO/vsyscall's OBJFILE is instead
|
||
managed by symfile-mem.c:add_vsyscall_page. */
|
||
if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range)
|
||
&& vsyscall_range.length != 0)
|
||
{
|
||
struct so_list **sop;
|
||
|
||
sop = &so_head;
|
||
while (*sop != NULL)
|
||
{
|
||
struct so_list *so = *sop;
|
||
|
||
/* We can't simply match the vDSO by starting address alone,
|
||
because lm_info->l_addr_inferior (and also l_addr) do not
|
||
necessarily represent the real starting address of the
|
||
ELF if the vDSO's ELF itself is "prelinked". The l_ld
|
||
field (the ".dynamic" section of the shared object)
|
||
always points at the absolute/resolved address though.
|
||
So check whether that address is inside the vDSO's
|
||
mapping instead.
|
||
|
||
E.g., on Linux 3.16 (x86_64) the vDSO is a regular
|
||
0-based ELF, and we see:
|
||
|
||
(gdb) info auxv
|
||
33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffb000
|
||
(gdb) p/x *_r_debug.r_map.l_next
|
||
$1 = {l_addr = 0x7ffff7ffb000, ..., l_ld = 0x7ffff7ffb318, ...}
|
||
|
||
And on Linux 2.6.32 (x86_64) we see:
|
||
|
||
(gdb) info auxv
|
||
33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffe000
|
||
(gdb) p/x *_r_debug.r_map.l_next
|
||
$5 = {l_addr = 0x7ffff88fe000, ..., l_ld = 0x7ffff7ffe580, ... }
|
||
|
||
Dumping that vDSO shows:
|
||
|
||
(gdb) info proc mappings
|
||
0x7ffff7ffe000 0x7ffff7fff000 0x1000 0 [vdso]
|
||
(gdb) dump memory vdso.bin 0x7ffff7ffe000 0x7ffff7fff000
|
||
# readelf -Wa vdso.bin
|
||
[...]
|
||
Entry point address: 0xffffffffff700700
|
||
[...]
|
||
Section Headers:
|
||
[Nr] Name Type Address Off Size
|
||
[ 0] NULL 0000000000000000 000000 000000
|
||
[ 1] .hash HASH ffffffffff700120 000120 000038
|
||
[ 2] .dynsym DYNSYM ffffffffff700158 000158 0000d8
|
||
[...]
|
||
[ 9] .dynamic DYNAMIC ffffffffff700580 000580 0000f0
|
||
*/
|
||
|
||
lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
|
||
|
||
if (address_in_mem_range (li->l_ld, &vsyscall_range))
|
||
{
|
||
*sop = so->next;
|
||
free_so (so);
|
||
break;
|
||
}
|
||
|
||
sop = &so->next;
|
||
}
|
||
}
|
||
|
||
return so_head;
|
||
}
|
||
|
||
/* Get the address of the link_map for a given OBJFILE. */
|
||
|
||
CORE_ADDR
|
||
svr4_fetch_objfile_link_map (struct objfile *objfile)
|
||
{
|
||
struct svr4_info *info = get_svr4_info (objfile->pspace);
|
||
|
||
/* Cause svr4_current_sos() to be run if it hasn't been already. */
|
||
if (info->main_lm_addr == 0)
|
||
solib_add (NULL, 0, auto_solib_add);
|
||
|
||
/* svr4_current_sos() will set main_lm_addr for the main executable. */
|
||
if (objfile == current_program_space->symfile_object_file)
|
||
return info->main_lm_addr;
|
||
|
||
/* The other link map addresses may be found by examining the list
|
||
of shared libraries. */
|
||
for (struct so_list *so : current_program_space->solibs ())
|
||
if (so->objfile == objfile)
|
||
{
|
||
lm_info_svr4 *li = (lm_info_svr4 *) so->lm_info;
|
||
|
||
return li->lm_addr;
|
||
}
|
||
|
||
/* Not found! */
|
||
return 0;
|
||
}
|
||
|
||
/* On some systems, the only way to recognize the link map entry for
|
||
the main executable file is by looking at its name. Return
|
||
non-zero iff SONAME matches one of the known main executable names. */
|
||
|
||
static int
|
||
match_main (const char *soname)
|
||
{
|
||
const char * const *mainp;
|
||
|
||
for (mainp = main_name_list; *mainp != NULL; mainp++)
|
||
{
|
||
if (strcmp (soname, *mainp) == 0)
|
||
return (1);
|
||
}
|
||
|
||
return (0);
|
||
}
|
||
|
||
/* Return 1 if PC lies in the dynamic symbol resolution code of the
|
||
SVR4 run time loader. */
|
||
|
||
int
|
||
svr4_in_dynsym_resolve_code (CORE_ADDR pc)
|
||
{
|
||
struct svr4_info *info = get_svr4_info (current_program_space);
|
||
|
||
return ((pc >= info->interp_text_sect_low
|
||
&& pc < info->interp_text_sect_high)
|
||
|| (pc >= info->interp_plt_sect_low
|
||
&& pc < info->interp_plt_sect_high)
|
||
|| in_plt_section (pc)
|
||
|| in_gnu_ifunc_stub (pc));
|
||
}
|
||
|
||
/* Given an executable's ABFD and target, compute the entry-point
|
||
address. */
|
||
|
||
static CORE_ADDR
|
||
exec_entry_point (struct bfd *abfd, struct target_ops *targ)
|
||
{
|
||
CORE_ADDR addr;
|
||
|
||
/* KevinB wrote ... for most targets, the address returned by
|
||
bfd_get_start_address() is the entry point for the start
|
||
function. But, for some targets, bfd_get_start_address() returns
|
||
the address of a function descriptor from which the entry point
|
||
address may be extracted. This address is extracted by
|
||
gdbarch_convert_from_func_ptr_addr(). The method
|
||
gdbarch_convert_from_func_ptr_addr() is the merely the identify
|
||
function for targets which don't use function descriptors. */
|
||
addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
|
||
bfd_get_start_address (abfd),
|
||
targ);
|
||
return gdbarch_addr_bits_remove (target_gdbarch (), addr);
|
||
}
|
||
|
||
/* A probe and its associated action. */
|
||
|
||
struct probe_and_action
|
||
{
|
||
/* The probe. */
|
||
probe *prob;
|
||
|
||
/* The relocated address of the probe. */
|
||
CORE_ADDR address;
|
||
|
||
/* The action. */
|
||
enum probe_action action;
|
||
|
||
/* The objfile where this probe was found. */
|
||
struct objfile *objfile;
|
||
};
|
||
|
||
/* Returns a hash code for the probe_and_action referenced by p. */
|
||
|
||
static hashval_t
|
||
hash_probe_and_action (const void *p)
|
||
{
|
||
const struct probe_and_action *pa = (const struct probe_and_action *) p;
|
||
|
||
return (hashval_t) pa->address;
|
||
}
|
||
|
||
/* Returns non-zero if the probe_and_actions referenced by p1 and p2
|
||
are equal. */
|
||
|
||
static int
|
||
equal_probe_and_action (const void *p1, const void *p2)
|
||
{
|
||
const struct probe_and_action *pa1 = (const struct probe_and_action *) p1;
|
||
const struct probe_and_action *pa2 = (const struct probe_and_action *) p2;
|
||
|
||
return pa1->address == pa2->address;
|
||
}
|
||
|
||
/* Traversal function for probes_table_remove_objfile_probes. */
|
||
|
||
static int
|
||
probes_table_htab_remove_objfile_probes (void **slot, void *info)
|
||
{
|
||
probe_and_action *pa = (probe_and_action *) *slot;
|
||
struct objfile *objfile = (struct objfile *) info;
|
||
|
||
if (pa->objfile == objfile)
|
||
htab_clear_slot (get_svr4_info (objfile->pspace)->probes_table.get (),
|
||
slot);
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Remove all probes that belong to OBJFILE from the probes table. */
|
||
|
||
static void
|
||
probes_table_remove_objfile_probes (struct objfile *objfile)
|
||
{
|
||
svr4_info *info = get_svr4_info (objfile->pspace);
|
||
if (info->probes_table != nullptr)
|
||
htab_traverse_noresize (info->probes_table.get (),
|
||
probes_table_htab_remove_objfile_probes, objfile);
|
||
}
|
||
|
||
/* Register a solib event probe and its associated action in the
|
||
probes table. */
|
||
|
||
static void
|
||
register_solib_event_probe (svr4_info *info, struct objfile *objfile,
|
||
probe *prob, CORE_ADDR address,
|
||
enum probe_action action)
|
||
{
|
||
struct probe_and_action lookup, *pa;
|
||
void **slot;
|
||
|
||
/* Create the probes table, if necessary. */
|
||
if (info->probes_table == NULL)
|
||
info->probes_table.reset (htab_create_alloc (1, hash_probe_and_action,
|
||
equal_probe_and_action,
|
||
xfree, xcalloc, xfree));
|
||
|
||
lookup.address = address;
|
||
slot = htab_find_slot (info->probes_table.get (), &lookup, INSERT);
|
||
gdb_assert (*slot == HTAB_EMPTY_ENTRY);
|
||
|
||
pa = XCNEW (struct probe_and_action);
|
||
pa->prob = prob;
|
||
pa->address = address;
|
||
pa->action = action;
|
||
pa->objfile = objfile;
|
||
|
||
*slot = pa;
|
||
}
|
||
|
||
/* Get the solib event probe at the specified location, and the
|
||
action associated with it. Returns NULL if no solib event probe
|
||
was found. */
|
||
|
||
static struct probe_and_action *
|
||
solib_event_probe_at (struct svr4_info *info, CORE_ADDR address)
|
||
{
|
||
struct probe_and_action lookup;
|
||
void **slot;
|
||
|
||
lookup.address = address;
|
||
slot = htab_find_slot (info->probes_table.get (), &lookup, NO_INSERT);
|
||
|
||
if (slot == NULL)
|
||
return NULL;
|
||
|
||
return (struct probe_and_action *) *slot;
|
||
}
|
||
|
||
/* Decide what action to take when the specified solib event probe is
|
||
hit. */
|
||
|
||
static enum probe_action
|
||
solib_event_probe_action (struct probe_and_action *pa)
|
||
{
|
||
enum probe_action action;
|
||
unsigned probe_argc = 0;
|
||
struct frame_info *frame = get_current_frame ();
|
||
|
||
action = pa->action;
|
||
if (action == DO_NOTHING || action == PROBES_INTERFACE_FAILED)
|
||
return action;
|
||
|
||
gdb_assert (action == FULL_RELOAD || action == UPDATE_OR_RELOAD);
|
||
|
||
/* Check that an appropriate number of arguments has been supplied.
|
||
We expect:
|
||
arg0: Lmid_t lmid (mandatory)
|
||
arg1: struct r_debug *debug_base (mandatory)
|
||
arg2: struct link_map *new (optional, for incremental updates) */
|
||
try
|
||
{
|
||
probe_argc = pa->prob->get_argument_count (get_frame_arch (frame));
|
||
}
|
||
catch (const gdb_exception_error &ex)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
probe_argc = 0;
|
||
}
|
||
|
||
/* If get_argument_count throws an exception, probe_argc will be set
|
||
to zero. However, if pa->prob does not have arguments, then
|
||
get_argument_count will succeed but probe_argc will also be zero.
|
||
Both cases happen because of different things, but they are
|
||
treated equally here: action will be set to
|
||
PROBES_INTERFACE_FAILED. */
|
||
if (probe_argc == 2)
|
||
action = FULL_RELOAD;
|
||
else if (probe_argc < 2)
|
||
action = PROBES_INTERFACE_FAILED;
|
||
|
||
return action;
|
||
}
|
||
|
||
/* Populate the shared object list by reading the entire list of
|
||
shared objects from the inferior. Handle special cases relating
|
||
to the first elements of the list. Returns nonzero on success. */
|
||
|
||
static int
|
||
solist_update_full (struct svr4_info *info)
|
||
{
|
||
free_solib_list (info);
|
||
info->solib_list = svr4_current_sos_direct (info);
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Update the shared object list starting from the link-map entry
|
||
passed by the linker in the probe's third argument. Returns
|
||
nonzero if the list was successfully updated, or zero to indicate
|
||
failure. */
|
||
|
||
static int
|
||
solist_update_incremental (struct svr4_info *info, CORE_ADDR lm)
|
||
{
|
||
struct so_list *tail;
|
||
CORE_ADDR prev_lm;
|
||
|
||
/* svr4_current_sos_direct contains logic to handle a number of
|
||
special cases relating to the first elements of the list. To
|
||
avoid duplicating this logic we defer to solist_update_full
|
||
if the list is empty. */
|
||
if (info->solib_list == NULL)
|
||
return 0;
|
||
|
||
/* Fall back to a full update if we are using a remote target
|
||
that does not support incremental transfers. */
|
||
if (info->using_xfer && !target_augmented_libraries_svr4_read ())
|
||
return 0;
|
||
|
||
/* Walk to the end of the list. */
|
||
for (tail = info->solib_list; tail->next != NULL; tail = tail->next)
|
||
/* Nothing. */;
|
||
|
||
lm_info_svr4 *li = (lm_info_svr4 *) tail->lm_info;
|
||
prev_lm = li->lm_addr;
|
||
|
||
/* Read the new objects. */
|
||
if (info->using_xfer)
|
||
{
|
||
struct svr4_library_list library_list;
|
||
char annex[64];
|
||
|
||
xsnprintf (annex, sizeof (annex), "start=%s;prev=%s",
|
||
phex_nz (lm, sizeof (lm)),
|
||
phex_nz (prev_lm, sizeof (prev_lm)));
|
||
if (!svr4_current_sos_via_xfer_libraries (&library_list, annex))
|
||
return 0;
|
||
|
||
tail->next = library_list.head;
|
||
}
|
||
else
|
||
{
|
||
struct so_list **link = &tail->next;
|
||
|
||
/* IGNORE_FIRST may safely be set to zero here because the
|
||
above check and deferral to solist_update_full ensures
|
||
that this call to svr4_read_so_list will never see the
|
||
first element. */
|
||
if (!svr4_read_so_list (info, lm, prev_lm, &link, 0))
|
||
return 0;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Disable the probes-based linker interface and revert to the
|
||
original interface. We don't reset the breakpoints as the
|
||
ones set up for the probes-based interface are adequate. */
|
||
|
||
static void
|
||
disable_probes_interface (svr4_info *info)
|
||
{
|
||
warning (_("Probes-based dynamic linker interface failed.\n"
|
||
"Reverting to original interface."));
|
||
|
||
free_probes_table (info);
|
||
free_solib_list (info);
|
||
}
|
||
|
||
/* Update the solib list as appropriate when using the
|
||
probes-based linker interface. Do nothing if using the
|
||
standard interface. */
|
||
|
||
static void
|
||
svr4_handle_solib_event (void)
|
||
{
|
||
struct svr4_info *info = get_svr4_info (current_program_space);
|
||
struct probe_and_action *pa;
|
||
enum probe_action action;
|
||
struct value *val = NULL;
|
||
CORE_ADDR pc, debug_base, lm = 0;
|
||
struct frame_info *frame = get_current_frame ();
|
||
|
||
/* Do nothing if not using the probes interface. */
|
||
if (info->probes_table == NULL)
|
||
return;
|
||
|
||
/* If anything goes wrong we revert to the original linker
|
||
interface. */
|
||
auto cleanup = make_scope_exit ([info] ()
|
||
{
|
||
disable_probes_interface (info);
|
||
});
|
||
|
||
pc = regcache_read_pc (get_current_regcache ());
|
||
pa = solib_event_probe_at (info, pc);
|
||
if (pa == NULL)
|
||
return;
|
||
|
||
action = solib_event_probe_action (pa);
|
||
if (action == PROBES_INTERFACE_FAILED)
|
||
return;
|
||
|
||
if (action == DO_NOTHING)
|
||
{
|
||
cleanup.release ();
|
||
return;
|
||
}
|
||
|
||
/* evaluate_argument looks up symbols in the dynamic linker
|
||
using find_pc_section. find_pc_section is accelerated by a cache
|
||
called the section map. The section map is invalidated every
|
||
time a shared library is loaded or unloaded, and if the inferior
|
||
is generating a lot of shared library events then the section map
|
||
will be updated every time svr4_handle_solib_event is called.
|
||
We called find_pc_section in svr4_create_solib_event_breakpoints,
|
||
so we can guarantee that the dynamic linker's sections are in the
|
||
section map. We can therefore inhibit section map updates across
|
||
these calls to evaluate_argument and save a lot of time. */
|
||
{
|
||
scoped_restore inhibit_updates
|
||
= inhibit_section_map_updates (current_program_space);
|
||
|
||
try
|
||
{
|
||
val = pa->prob->evaluate_argument (1, frame);
|
||
}
|
||
catch (const gdb_exception_error &ex)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
val = NULL;
|
||
}
|
||
|
||
if (val == NULL)
|
||
return;
|
||
|
||
debug_base = value_as_address (val);
|
||
if (debug_base == 0)
|
||
return;
|
||
|
||
/* Always locate the debug struct, in case it moved. */
|
||
info->debug_base = 0;
|
||
if (locate_base (info) == 0)
|
||
{
|
||
/* It's possible for the reloc_complete probe to be triggered before
|
||
the linker has set the DT_DEBUG pointer (for example, when the
|
||
linker has finished relocating an LD_AUDIT library or its
|
||
dependencies). Since we can't yet handle libraries from other link
|
||
namespaces, we don't lose anything by ignoring them here. */
|
||
struct value *link_map_id_val;
|
||
try
|
||
{
|
||
link_map_id_val = pa->prob->evaluate_argument (0, frame);
|
||
}
|
||
catch (const gdb_exception_error)
|
||
{
|
||
link_map_id_val = NULL;
|
||
}
|
||
/* glibc and illumos' libc both define LM_ID_BASE as zero. */
|
||
if (link_map_id_val != NULL && value_as_long (link_map_id_val) != 0)
|
||
action = DO_NOTHING;
|
||
else
|
||
return;
|
||
}
|
||
|
||
/* GDB does not currently support libraries loaded via dlmopen
|
||
into namespaces other than the initial one. We must ignore
|
||
any namespace other than the initial namespace here until
|
||
support for this is added to GDB. */
|
||
if (debug_base != info->debug_base)
|
||
action = DO_NOTHING;
|
||
|
||
if (action == UPDATE_OR_RELOAD)
|
||
{
|
||
try
|
||
{
|
||
val = pa->prob->evaluate_argument (2, frame);
|
||
}
|
||
catch (const gdb_exception_error &ex)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
return;
|
||
}
|
||
|
||
if (val != NULL)
|
||
lm = value_as_address (val);
|
||
|
||
if (lm == 0)
|
||
action = FULL_RELOAD;
|
||
}
|
||
|
||
/* Resume section map updates. Closing the scope is
|
||
sufficient. */
|
||
}
|
||
|
||
if (action == UPDATE_OR_RELOAD)
|
||
{
|
||
if (!solist_update_incremental (info, lm))
|
||
action = FULL_RELOAD;
|
||
}
|
||
|
||
if (action == FULL_RELOAD)
|
||
{
|
||
if (!solist_update_full (info))
|
||
return;
|
||
}
|
||
|
||
cleanup.release ();
|
||
}
|
||
|
||
/* Helper function for svr4_update_solib_event_breakpoints. */
|
||
|
||
static bool
|
||
svr4_update_solib_event_breakpoint (struct breakpoint *b)
|
||
{
|
||
if (b->type != bp_shlib_event)
|
||
{
|
||
/* Continue iterating. */
|
||
return false;
|
||
}
|
||
|
||
for (bp_location *loc : b->locations ())
|
||
{
|
||
struct svr4_info *info;
|
||
struct probe_and_action *pa;
|
||
|
||
info = solib_svr4_pspace_data.get (loc->pspace);
|
||
if (info == NULL || info->probes_table == NULL)
|
||
continue;
|
||
|
||
pa = solib_event_probe_at (info, loc->address);
|
||
if (pa == NULL)
|
||
continue;
|
||
|
||
if (pa->action == DO_NOTHING)
|
||
{
|
||
if (b->enable_state == bp_disabled && stop_on_solib_events)
|
||
enable_breakpoint (b);
|
||
else if (b->enable_state == bp_enabled && !stop_on_solib_events)
|
||
disable_breakpoint (b);
|
||
}
|
||
|
||
break;
|
||
}
|
||
|
||
/* Continue iterating. */
|
||
return false;
|
||
}
|
||
|
||
/* Enable or disable optional solib event breakpoints as appropriate.
|
||
Called whenever stop_on_solib_events is changed. */
|
||
|
||
static void
|
||
svr4_update_solib_event_breakpoints (void)
|
||
{
|
||
for (breakpoint *bp : all_breakpoints_safe ())
|
||
svr4_update_solib_event_breakpoint (bp);
|
||
}
|
||
|
||
/* Create and register solib event breakpoints. PROBES is an array
|
||
of NUM_PROBES elements, each of which is vector of probes. A
|
||
solib event breakpoint will be created and registered for each
|
||
probe. */
|
||
|
||
static void
|
||
svr4_create_probe_breakpoints (svr4_info *info, struct gdbarch *gdbarch,
|
||
const std::vector<probe *> *probes,
|
||
struct objfile *objfile)
|
||
{
|
||
for (int i = 0; i < NUM_PROBES; i++)
|
||
{
|
||
enum probe_action action = probe_info[i].action;
|
||
|
||
for (probe *p : probes[i])
|
||
{
|
||
CORE_ADDR address = p->get_relocated_address (objfile);
|
||
|
||
create_solib_event_breakpoint (gdbarch, address);
|
||
register_solib_event_probe (info, objfile, p, address, action);
|
||
}
|
||
}
|
||
|
||
svr4_update_solib_event_breakpoints ();
|
||
}
|
||
|
||
/* Find all the glibc named probes. Only if all of the probes are found, then
|
||
create them and return true. Otherwise return false. If WITH_PREFIX is set
|
||
then add "rtld" to the front of the probe names. */
|
||
static bool
|
||
svr4_find_and_create_probe_breakpoints (svr4_info *info,
|
||
struct gdbarch *gdbarch,
|
||
struct obj_section *os,
|
||
bool with_prefix)
|
||
{
|
||
std::vector<probe *> probes[NUM_PROBES];
|
||
|
||
for (int i = 0; i < NUM_PROBES; i++)
|
||
{
|
||
const char *name = probe_info[i].name;
|
||
char buf[32];
|
||
|
||
/* Fedora 17 and Red Hat Enterprise Linux 6.2-6.4 shipped with an early
|
||
version of the probes code in which the probes' names were prefixed
|
||
with "rtld_" and the "map_failed" probe did not exist. The locations
|
||
of the probes are otherwise the same, so we check for probes with
|
||
prefixed names if probes with unprefixed names are not present. */
|
||
if (with_prefix)
|
||
{
|
||
xsnprintf (buf, sizeof (buf), "rtld_%s", name);
|
||
name = buf;
|
||
}
|
||
|
||
probes[i] = find_probes_in_objfile (os->objfile, "rtld", name);
|
||
|
||
/* The "map_failed" probe did not exist in early
|
||
versions of the probes code in which the probes'
|
||
names were prefixed with "rtld_". */
|
||
if (with_prefix && streq (name, "rtld_map_failed"))
|
||
continue;
|
||
|
||
/* Ensure at least one probe for the current name was found. */
|
||
if (probes[i].empty ())
|
||
return false;
|
||
|
||
/* Ensure probe arguments can be evaluated. */
|
||
for (probe *p : probes[i])
|
||
{
|
||
if (!p->can_evaluate_arguments ())
|
||
return false;
|
||
/* This will fail if the probe is invalid. This has been seen on Arm
|
||
due to references to symbols that have been resolved away. */
|
||
try
|
||
{
|
||
p->get_argument_count (gdbarch);
|
||
}
|
||
catch (const gdb_exception_error &ex)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
warning (_("Initializing probes-based dynamic linker interface "
|
||
"failed.\nReverting to original interface."));
|
||
return false;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* All probes found. Now create them. */
|
||
svr4_create_probe_breakpoints (info, gdbarch, probes, os->objfile);
|
||
return true;
|
||
}
|
||
|
||
/* Both the SunOS and the SVR4 dynamic linkers call a marker function
|
||
before and after mapping and unmapping shared libraries. The sole
|
||
purpose of this method is to allow debuggers to set a breakpoint so
|
||
they can track these changes.
|
||
|
||
Some versions of the glibc dynamic linker contain named probes
|
||
to allow more fine grained stopping. Given the address of the
|
||
original marker function, this function attempts to find these
|
||
probes, and if found, sets breakpoints on those instead. If the
|
||
probes aren't found, a single breakpoint is set on the original
|
||
marker function. */
|
||
|
||
static void
|
||
svr4_create_solib_event_breakpoints (svr4_info *info, struct gdbarch *gdbarch,
|
||
CORE_ADDR address)
|
||
{
|
||
struct obj_section *os = find_pc_section (address);
|
||
|
||
if (os == nullptr
|
||
|| (!svr4_find_and_create_probe_breakpoints (info, gdbarch, os, false)
|
||
&& !svr4_find_and_create_probe_breakpoints (info, gdbarch, os, true)))
|
||
create_solib_event_breakpoint (gdbarch, address);
|
||
}
|
||
|
||
/* Helper function for gdb_bfd_lookup_symbol. */
|
||
|
||
static int
|
||
cmp_name_and_sec_flags (const asymbol *sym, const void *data)
|
||
{
|
||
return (strcmp (sym->name, (const char *) data) == 0
|
||
&& (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0);
|
||
}
|
||
/* Arrange for dynamic linker to hit breakpoint.
|
||
|
||
Both the SunOS and the SVR4 dynamic linkers have, as part of their
|
||
debugger interface, support for arranging for the inferior to hit
|
||
a breakpoint after mapping in the shared libraries. This function
|
||
enables that breakpoint.
|
||
|
||
For SunOS, there is a special flag location (in_debugger) which we
|
||
set to 1. When the dynamic linker sees this flag set, it will set
|
||
a breakpoint at a location known only to itself, after saving the
|
||
original contents of that place and the breakpoint address itself,
|
||
in it's own internal structures. When we resume the inferior, it
|
||
will eventually take a SIGTRAP when it runs into the breakpoint.
|
||
We handle this (in a different place) by restoring the contents of
|
||
the breakpointed location (which is only known after it stops),
|
||
chasing around to locate the shared libraries that have been
|
||
loaded, then resuming.
|
||
|
||
For SVR4, the debugger interface structure contains a member (r_brk)
|
||
which is statically initialized at the time the shared library is
|
||
built, to the offset of a function (_r_debug_state) which is guaran-
|
||
teed to be called once before mapping in a library, and again when
|
||
the mapping is complete. At the time we are examining this member,
|
||
it contains only the unrelocated offset of the function, so we have
|
||
to do our own relocation. Later, when the dynamic linker actually
|
||
runs, it relocates r_brk to be the actual address of _r_debug_state().
|
||
|
||
The debugger interface structure also contains an enumeration which
|
||
is set to either RT_ADD or RT_DELETE prior to changing the mapping,
|
||
depending upon whether or not the library is being mapped or unmapped,
|
||
and then set to RT_CONSISTENT after the library is mapped/unmapped. */
|
||
|
||
static int
|
||
enable_break (struct svr4_info *info, int from_tty)
|
||
{
|
||
struct bound_minimal_symbol msymbol;
|
||
const char * const *bkpt_namep;
|
||
asection *interp_sect;
|
||
CORE_ADDR sym_addr;
|
||
|
||
info->interp_text_sect_low = info->interp_text_sect_high = 0;
|
||
info->interp_plt_sect_low = info->interp_plt_sect_high = 0;
|
||
|
||
/* If we already have a shared library list in the target, and
|
||
r_debug contains r_brk, set the breakpoint there - this should
|
||
mean r_brk has already been relocated. Assume the dynamic linker
|
||
is the object containing r_brk. */
|
||
|
||
solib_add (NULL, from_tty, auto_solib_add);
|
||
sym_addr = 0;
|
||
if (info->debug_base && solib_svr4_r_map (info) != 0)
|
||
sym_addr = solib_svr4_r_brk (info);
|
||
|
||
if (sym_addr != 0)
|
||
{
|
||
struct obj_section *os;
|
||
|
||
sym_addr = gdbarch_addr_bits_remove
|
||
(target_gdbarch (),
|
||
gdbarch_convert_from_func_ptr_addr
|
||
(target_gdbarch (), sym_addr, current_inferior ()->top_target ()));
|
||
|
||
/* On at least some versions of Solaris there's a dynamic relocation
|
||
on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
|
||
we get control before the dynamic linker has self-relocated.
|
||
Check if SYM_ADDR is in a known section, if it is assume we can
|
||
trust its value. This is just a heuristic though, it could go away
|
||
or be replaced if it's getting in the way.
|
||
|
||
On ARM we need to know whether the ISA of rtld_db_dlactivity (or
|
||
however it's spelled in your particular system) is ARM or Thumb.
|
||
That knowledge is encoded in the address, if it's Thumb the low bit
|
||
is 1. However, we've stripped that info above and it's not clear
|
||
what all the consequences are of passing a non-addr_bits_remove'd
|
||
address to svr4_create_solib_event_breakpoints. The call to
|
||
find_pc_section verifies we know about the address and have some
|
||
hope of computing the right kind of breakpoint to use (via
|
||
symbol info). It does mean that GDB needs to be pointed at a
|
||
non-stripped version of the dynamic linker in order to obtain
|
||
information it already knows about. Sigh. */
|
||
|
||
os = find_pc_section (sym_addr);
|
||
if (os != NULL)
|
||
{
|
||
/* Record the relocated start and end address of the dynamic linker
|
||
text and plt section for svr4_in_dynsym_resolve_code. */
|
||
bfd *tmp_bfd;
|
||
CORE_ADDR load_addr;
|
||
|
||
tmp_bfd = os->objfile->obfd;
|
||
load_addr = os->objfile->text_section_offset ();
|
||
|
||
interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
|
||
if (interp_sect)
|
||
{
|
||
info->interp_text_sect_low
|
||
= bfd_section_vma (interp_sect) + load_addr;
|
||
info->interp_text_sect_high
|
||
= info->interp_text_sect_low + bfd_section_size (interp_sect);
|
||
}
|
||
interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
|
||
if (interp_sect)
|
||
{
|
||
info->interp_plt_sect_low
|
||
= bfd_section_vma (interp_sect) + load_addr;
|
||
info->interp_plt_sect_high
|
||
= info->interp_plt_sect_low + bfd_section_size (interp_sect);
|
||
}
|
||
|
||
svr4_create_solib_event_breakpoints (info, target_gdbarch (), sym_addr);
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
/* Find the program interpreter; if not found, warn the user and drop
|
||
into the old breakpoint at symbol code. */
|
||
gdb::optional<gdb::byte_vector> interp_name_holder
|
||
= find_program_interpreter ();
|
||
if (interp_name_holder)
|
||
{
|
||
const char *interp_name = (const char *) interp_name_holder->data ();
|
||
CORE_ADDR load_addr = 0;
|
||
int load_addr_found = 0;
|
||
int loader_found_in_list = 0;
|
||
struct target_ops *tmp_bfd_target;
|
||
|
||
sym_addr = 0;
|
||
|
||
/* Now we need to figure out where the dynamic linker was
|
||
loaded so that we can load its symbols and place a breakpoint
|
||
in the dynamic linker itself.
|
||
|
||
This address is stored on the stack. However, I've been unable
|
||
to find any magic formula to find it for Solaris (appears to
|
||
be trivial on GNU/Linux). Therefore, we have to try an alternate
|
||
mechanism to find the dynamic linker's base address. */
|
||
|
||
gdb_bfd_ref_ptr tmp_bfd;
|
||
try
|
||
{
|
||
tmp_bfd = solib_bfd_open (interp_name);
|
||
}
|
||
catch (const gdb_exception &ex)
|
||
{
|
||
}
|
||
|
||
if (tmp_bfd == NULL)
|
||
goto bkpt_at_symbol;
|
||
|
||
/* Now convert the TMP_BFD into a target. That way target, as
|
||
well as BFD operations can be used. */
|
||
tmp_bfd_target = target_bfd_reopen (tmp_bfd);
|
||
|
||
/* On a running target, we can get the dynamic linker's base
|
||
address from the shared library table. */
|
||
for (struct so_list *so : current_program_space->solibs ())
|
||
{
|
||
if (svr4_same_1 (interp_name, so->so_original_name))
|
||
{
|
||
load_addr_found = 1;
|
||
loader_found_in_list = 1;
|
||
load_addr = lm_addr_check (so, tmp_bfd.get ());
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* If we were not able to find the base address of the loader
|
||
from our so_list, then try using the AT_BASE auxilliary entry. */
|
||
if (!load_addr_found)
|
||
if (target_auxv_search (current_inferior ()->top_target (),
|
||
AT_BASE, &load_addr) > 0)
|
||
{
|
||
int addr_bit = gdbarch_addr_bit (target_gdbarch ());
|
||
|
||
/* Ensure LOAD_ADDR has proper sign in its possible upper bits so
|
||
that `+ load_addr' will overflow CORE_ADDR width not creating
|
||
invalid addresses like 0x101234567 for 32bit inferiors on 64bit
|
||
GDB. */
|
||
|
||
if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
|
||
{
|
||
CORE_ADDR space_size = (CORE_ADDR) 1 << addr_bit;
|
||
CORE_ADDR tmp_entry_point = exec_entry_point (tmp_bfd.get (),
|
||
tmp_bfd_target);
|
||
|
||
gdb_assert (load_addr < space_size);
|
||
|
||
/* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
|
||
64bit ld.so with 32bit executable, it should not happen. */
|
||
|
||
if (tmp_entry_point < space_size
|
||
&& tmp_entry_point + load_addr >= space_size)
|
||
load_addr -= space_size;
|
||
}
|
||
|
||
load_addr_found = 1;
|
||
}
|
||
|
||
/* Otherwise we find the dynamic linker's base address by examining
|
||
the current pc (which should point at the entry point for the
|
||
dynamic linker) and subtracting the offset of the entry point.
|
||
|
||
This is more fragile than the previous approaches, but is a good
|
||
fallback method because it has actually been working well in
|
||
most cases. */
|
||
if (!load_addr_found)
|
||
{
|
||
struct regcache *regcache
|
||
= get_thread_arch_regcache (current_inferior ()->process_target (),
|
||
inferior_ptid, target_gdbarch ());
|
||
|
||
load_addr = (regcache_read_pc (regcache)
|
||
- exec_entry_point (tmp_bfd.get (), tmp_bfd_target));
|
||
}
|
||
|
||
if (!loader_found_in_list)
|
||
{
|
||
info->debug_loader_name = xstrdup (interp_name);
|
||
info->debug_loader_offset_p = 1;
|
||
info->debug_loader_offset = load_addr;
|
||
solib_add (NULL, from_tty, auto_solib_add);
|
||
}
|
||
|
||
/* Record the relocated start and end address of the dynamic linker
|
||
text and plt section for svr4_in_dynsym_resolve_code. */
|
||
interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".text");
|
||
if (interp_sect)
|
||
{
|
||
info->interp_text_sect_low
|
||
= bfd_section_vma (interp_sect) + load_addr;
|
||
info->interp_text_sect_high
|
||
= info->interp_text_sect_low + bfd_section_size (interp_sect);
|
||
}
|
||
interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".plt");
|
||
if (interp_sect)
|
||
{
|
||
info->interp_plt_sect_low
|
||
= bfd_section_vma (interp_sect) + load_addr;
|
||
info->interp_plt_sect_high
|
||
= info->interp_plt_sect_low + bfd_section_size (interp_sect);
|
||
}
|
||
|
||
/* Now try to set a breakpoint in the dynamic linker. */
|
||
for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
|
||
{
|
||
sym_addr = gdb_bfd_lookup_symbol (tmp_bfd.get (),
|
||
cmp_name_and_sec_flags,
|
||
*bkpt_namep);
|
||
if (sym_addr != 0)
|
||
break;
|
||
}
|
||
|
||
if (sym_addr != 0)
|
||
/* Convert 'sym_addr' from a function pointer to an address.
|
||
Because we pass tmp_bfd_target instead of the current
|
||
target, this will always produce an unrelocated value. */
|
||
sym_addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
|
||
sym_addr,
|
||
tmp_bfd_target);
|
||
|
||
/* We're done with both the temporary bfd and target. Closing
|
||
the target closes the underlying bfd, because it holds the
|
||
only remaining reference. */
|
||
target_close (tmp_bfd_target);
|
||
|
||
if (sym_addr != 0)
|
||
{
|
||
svr4_create_solib_event_breakpoints (info, target_gdbarch (),
|
||
load_addr + sym_addr);
|
||
return 1;
|
||
}
|
||
|
||
/* For whatever reason we couldn't set a breakpoint in the dynamic
|
||
linker. Warn and drop into the old code. */
|
||
bkpt_at_symbol:
|
||
warning (_("Unable to find dynamic linker breakpoint function.\n"
|
||
"GDB will be unable to debug shared library initializers\n"
|
||
"and track explicitly loaded dynamic code."));
|
||
}
|
||
|
||
/* Scan through the lists of symbols, trying to look up the symbol and
|
||
set a breakpoint there. Terminate loop when we/if we succeed. */
|
||
|
||
objfile *objf = current_program_space->symfile_object_file;
|
||
for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
|
||
{
|
||
msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, objf);
|
||
if ((msymbol.minsym != NULL)
|
||
&& (BMSYMBOL_VALUE_ADDRESS (msymbol) != 0))
|
||
{
|
||
sym_addr = BMSYMBOL_VALUE_ADDRESS (msymbol);
|
||
sym_addr = gdbarch_convert_from_func_ptr_addr
|
||
(target_gdbarch (), sym_addr, current_inferior ()->top_target ());
|
||
svr4_create_solib_event_breakpoints (info, target_gdbarch (),
|
||
sym_addr);
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
if (interp_name_holder && !current_inferior ()->attach_flag)
|
||
{
|
||
for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
|
||
{
|
||
msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, objf);
|
||
if ((msymbol.minsym != NULL)
|
||
&& (BMSYMBOL_VALUE_ADDRESS (msymbol) != 0))
|
||
{
|
||
sym_addr = BMSYMBOL_VALUE_ADDRESS (msymbol);
|
||
sym_addr = gdbarch_convert_from_func_ptr_addr
|
||
(target_gdbarch (), sym_addr,
|
||
current_inferior ()->top_target ());
|
||
svr4_create_solib_event_breakpoints (info, target_gdbarch (),
|
||
sym_addr);
|
||
return 1;
|
||
}
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* Read the ELF program headers from ABFD. */
|
||
|
||
static gdb::optional<gdb::byte_vector>
|
||
read_program_headers_from_bfd (bfd *abfd)
|
||
{
|
||
Elf_Internal_Ehdr *ehdr = elf_elfheader (abfd);
|
||
int phdrs_size = ehdr->e_phnum * ehdr->e_phentsize;
|
||
if (phdrs_size == 0)
|
||
return {};
|
||
|
||
gdb::byte_vector buf (phdrs_size);
|
||
if (bfd_seek (abfd, ehdr->e_phoff, SEEK_SET) != 0
|
||
|| bfd_bread (buf.data (), phdrs_size, abfd) != phdrs_size)
|
||
return {};
|
||
|
||
return buf;
|
||
}
|
||
|
||
/* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
|
||
exec_bfd. Otherwise return 0.
|
||
|
||
We relocate all of the sections by the same amount. This
|
||
behavior is mandated by recent editions of the System V ABI.
|
||
According to the System V Application Binary Interface,
|
||
Edition 4.1, page 5-5:
|
||
|
||
... Though the system chooses virtual addresses for
|
||
individual processes, it maintains the segments' relative
|
||
positions. Because position-independent code uses relative
|
||
addressing between segments, the difference between
|
||
virtual addresses in memory must match the difference
|
||
between virtual addresses in the file. The difference
|
||
between the virtual address of any segment in memory and
|
||
the corresponding virtual address in the file is thus a
|
||
single constant value for any one executable or shared
|
||
object in a given process. This difference is the base
|
||
address. One use of the base address is to relocate the
|
||
memory image of the program during dynamic linking.
|
||
|
||
The same language also appears in Edition 4.0 of the System V
|
||
ABI and is left unspecified in some of the earlier editions.
|
||
|
||
Decide if the objfile needs to be relocated. As indicated above, we will
|
||
only be here when execution is stopped. But during attachment PC can be at
|
||
arbitrary address therefore regcache_read_pc can be misleading (contrary to
|
||
the auxv AT_ENTRY value). Moreover for executable with interpreter section
|
||
regcache_read_pc would point to the interpreter and not the main executable.
|
||
|
||
So, to summarize, relocations are necessary when the start address obtained
|
||
from the executable is different from the address in auxv AT_ENTRY entry.
|
||
|
||
[ The astute reader will note that we also test to make sure that
|
||
the executable in question has the DYNAMIC flag set. It is my
|
||
opinion that this test is unnecessary (undesirable even). It
|
||
was added to avoid inadvertent relocation of an executable
|
||
whose e_type member in the ELF header is not ET_DYN. There may
|
||
be a time in the future when it is desirable to do relocations
|
||
on other types of files as well in which case this condition
|
||
should either be removed or modified to accomodate the new file
|
||
type. - Kevin, Nov 2000. ] */
|
||
|
||
static int
|
||
svr4_exec_displacement (CORE_ADDR *displacementp)
|
||
{
|
||
/* ENTRY_POINT is a possible function descriptor - before
|
||
a call to gdbarch_convert_from_func_ptr_addr. */
|
||
CORE_ADDR entry_point, exec_displacement;
|
||
|
||
if (current_program_space->exec_bfd () == NULL)
|
||
return 0;
|
||
|
||
/* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
|
||
being executed themselves and PIE (Position Independent Executable)
|
||
executables are ET_DYN. */
|
||
|
||
if ((bfd_get_file_flags (current_program_space->exec_bfd ()) & DYNAMIC) == 0)
|
||
return 0;
|
||
|
||
if (target_auxv_search (current_inferior ()->top_target (),
|
||
AT_ENTRY, &entry_point) <= 0)
|
||
return 0;
|
||
|
||
exec_displacement
|
||
= entry_point - bfd_get_start_address (current_program_space->exec_bfd ());
|
||
|
||
/* Verify the EXEC_DISPLACEMENT candidate complies with the required page
|
||
alignment. It is cheaper than the program headers comparison below. */
|
||
|
||
if (bfd_get_flavour (current_program_space->exec_bfd ())
|
||
== bfd_target_elf_flavour)
|
||
{
|
||
const struct elf_backend_data *elf
|
||
= get_elf_backend_data (current_program_space->exec_bfd ());
|
||
|
||
/* p_align of PT_LOAD segments does not specify any alignment but
|
||
only congruency of addresses:
|
||
p_offset % p_align == p_vaddr % p_align
|
||
Kernel is free to load the executable with lower alignment. */
|
||
|
||
if ((exec_displacement & (elf->minpagesize - 1)) != 0)
|
||
return 0;
|
||
}
|
||
|
||
/* Verify that the auxilliary vector describes the same file as exec_bfd, by
|
||
comparing their program headers. If the program headers in the auxilliary
|
||
vector do not match the program headers in the executable, then we are
|
||
looking at a different file than the one used by the kernel - for
|
||
instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
|
||
|
||
if (bfd_get_flavour (current_program_space->exec_bfd ())
|
||
== bfd_target_elf_flavour)
|
||
{
|
||
/* Be optimistic and return 0 only if GDB was able to verify the headers
|
||
really do not match. */
|
||
int arch_size;
|
||
|
||
gdb::optional<gdb::byte_vector> phdrs_target
|
||
= read_program_header (-1, &arch_size, NULL);
|
||
gdb::optional<gdb::byte_vector> phdrs_binary
|
||
= read_program_headers_from_bfd (current_program_space->exec_bfd ());
|
||
if (phdrs_target && phdrs_binary)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
|
||
|
||
/* We are dealing with three different addresses. EXEC_BFD
|
||
represents current address in on-disk file. target memory content
|
||
may be different from EXEC_BFD as the file may have been prelinked
|
||
to a different address after the executable has been loaded.
|
||
Moreover the address of placement in target memory can be
|
||
different from what the program headers in target memory say -
|
||
this is the goal of PIE.
|
||
|
||
Detected DISPLACEMENT covers both the offsets of PIE placement and
|
||
possible new prelink performed after start of the program. Here
|
||
relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
|
||
content offset for the verification purpose. */
|
||
|
||
if (phdrs_target->size () != phdrs_binary->size ()
|
||
|| bfd_get_arch_size (current_program_space->exec_bfd ()) != arch_size)
|
||
return 0;
|
||
else if (arch_size == 32
|
||
&& phdrs_target->size () >= sizeof (Elf32_External_Phdr)
|
||
&& phdrs_target->size () % sizeof (Elf32_External_Phdr) == 0)
|
||
{
|
||
Elf_Internal_Ehdr *ehdr2
|
||
= elf_tdata (current_program_space->exec_bfd ())->elf_header;
|
||
Elf_Internal_Phdr *phdr2
|
||
= elf_tdata (current_program_space->exec_bfd ())->phdr;
|
||
CORE_ADDR displacement = 0;
|
||
int i;
|
||
|
||
/* DISPLACEMENT could be found more easily by the difference of
|
||
ehdr2->e_entry. But we haven't read the ehdr yet, and we
|
||
already have enough information to compute that displacement
|
||
with what we've read. */
|
||
|
||
for (i = 0; i < ehdr2->e_phnum; i++)
|
||
if (phdr2[i].p_type == PT_LOAD)
|
||
{
|
||
Elf32_External_Phdr *phdrp;
|
||
gdb_byte *buf_vaddr_p, *buf_paddr_p;
|
||
CORE_ADDR vaddr, paddr;
|
||
CORE_ADDR displacement_vaddr = 0;
|
||
CORE_ADDR displacement_paddr = 0;
|
||
|
||
phdrp = &((Elf32_External_Phdr *) phdrs_target->data ())[i];
|
||
buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
|
||
buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
|
||
|
||
vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
|
||
byte_order);
|
||
displacement_vaddr = vaddr - phdr2[i].p_vaddr;
|
||
|
||
paddr = extract_unsigned_integer (buf_paddr_p, 4,
|
||
byte_order);
|
||
displacement_paddr = paddr - phdr2[i].p_paddr;
|
||
|
||
if (displacement_vaddr == displacement_paddr)
|
||
displacement = displacement_vaddr;
|
||
|
||
break;
|
||
}
|
||
|
||
/* Now compare program headers from the target and the binary
|
||
with optional DISPLACEMENT. */
|
||
|
||
for (i = 0;
|
||
i < phdrs_target->size () / sizeof (Elf32_External_Phdr);
|
||
i++)
|
||
{
|
||
Elf32_External_Phdr *phdrp;
|
||
Elf32_External_Phdr *phdr2p;
|
||
gdb_byte *buf_vaddr_p, *buf_paddr_p;
|
||
CORE_ADDR vaddr, paddr;
|
||
asection *plt2_asect;
|
||
|
||
phdrp = &((Elf32_External_Phdr *) phdrs_target->data ())[i];
|
||
buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
|
||
buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
|
||
phdr2p = &((Elf32_External_Phdr *) phdrs_binary->data ())[i];
|
||
|
||
/* PT_GNU_STACK is an exception by being never relocated by
|
||
prelink as its addresses are always zero. */
|
||
|
||
if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
|
||
continue;
|
||
|
||
/* Check also other adjustment combinations - PR 11786. */
|
||
|
||
vaddr = extract_unsigned_integer (buf_vaddr_p, 4,
|
||
byte_order);
|
||
vaddr -= displacement;
|
||
store_unsigned_integer (buf_vaddr_p, 4, byte_order, vaddr);
|
||
|
||
paddr = extract_unsigned_integer (buf_paddr_p, 4,
|
||
byte_order);
|
||
paddr -= displacement;
|
||
store_unsigned_integer (buf_paddr_p, 4, byte_order, paddr);
|
||
|
||
if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
|
||
continue;
|
||
|
||
/* Strip modifies the flags and alignment of PT_GNU_RELRO.
|
||
CentOS-5 has problems with filesz, memsz as well.
|
||
Strip also modifies memsz of PT_TLS.
|
||
See PR 11786. */
|
||
if (phdr2[i].p_type == PT_GNU_RELRO
|
||
|| phdr2[i].p_type == PT_TLS)
|
||
{
|
||
Elf32_External_Phdr tmp_phdr = *phdrp;
|
||
Elf32_External_Phdr tmp_phdr2 = *phdr2p;
|
||
|
||
memset (tmp_phdr.p_filesz, 0, 4);
|
||
memset (tmp_phdr.p_memsz, 0, 4);
|
||
memset (tmp_phdr.p_flags, 0, 4);
|
||
memset (tmp_phdr.p_align, 0, 4);
|
||
memset (tmp_phdr2.p_filesz, 0, 4);
|
||
memset (tmp_phdr2.p_memsz, 0, 4);
|
||
memset (tmp_phdr2.p_flags, 0, 4);
|
||
memset (tmp_phdr2.p_align, 0, 4);
|
||
|
||
if (memcmp (&tmp_phdr, &tmp_phdr2, sizeof (tmp_phdr))
|
||
== 0)
|
||
continue;
|
||
}
|
||
|
||
/* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
|
||
bfd *exec_bfd = current_program_space->exec_bfd ();
|
||
plt2_asect = bfd_get_section_by_name (exec_bfd, ".plt");
|
||
if (plt2_asect)
|
||
{
|
||
int content2;
|
||
gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
|
||
CORE_ADDR filesz;
|
||
|
||
content2 = (bfd_section_flags (plt2_asect)
|
||
& SEC_HAS_CONTENTS) != 0;
|
||
|
||
filesz = extract_unsigned_integer (buf_filesz_p, 4,
|
||
byte_order);
|
||
|
||
/* PLT2_ASECT is from on-disk file (exec_bfd) while
|
||
FILESZ is from the in-memory image. */
|
||
if (content2)
|
||
filesz += bfd_section_size (plt2_asect);
|
||
else
|
||
filesz -= bfd_section_size (plt2_asect);
|
||
|
||
store_unsigned_integer (buf_filesz_p, 4, byte_order,
|
||
filesz);
|
||
|
||
if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
|
||
continue;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
}
|
||
else if (arch_size == 64
|
||
&& phdrs_target->size () >= sizeof (Elf64_External_Phdr)
|
||
&& phdrs_target->size () % sizeof (Elf64_External_Phdr) == 0)
|
||
{
|
||
Elf_Internal_Ehdr *ehdr2
|
||
= elf_tdata (current_program_space->exec_bfd ())->elf_header;
|
||
Elf_Internal_Phdr *phdr2
|
||
= elf_tdata (current_program_space->exec_bfd ())->phdr;
|
||
CORE_ADDR displacement = 0;
|
||
int i;
|
||
|
||
/* DISPLACEMENT could be found more easily by the difference of
|
||
ehdr2->e_entry. But we haven't read the ehdr yet, and we
|
||
already have enough information to compute that displacement
|
||
with what we've read. */
|
||
|
||
for (i = 0; i < ehdr2->e_phnum; i++)
|
||
if (phdr2[i].p_type == PT_LOAD)
|
||
{
|
||
Elf64_External_Phdr *phdrp;
|
||
gdb_byte *buf_vaddr_p, *buf_paddr_p;
|
||
CORE_ADDR vaddr, paddr;
|
||
CORE_ADDR displacement_vaddr = 0;
|
||
CORE_ADDR displacement_paddr = 0;
|
||
|
||
phdrp = &((Elf64_External_Phdr *) phdrs_target->data ())[i];
|
||
buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
|
||
buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
|
||
|
||
vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
|
||
byte_order);
|
||
displacement_vaddr = vaddr - phdr2[i].p_vaddr;
|
||
|
||
paddr = extract_unsigned_integer (buf_paddr_p, 8,
|
||
byte_order);
|
||
displacement_paddr = paddr - phdr2[i].p_paddr;
|
||
|
||
if (displacement_vaddr == displacement_paddr)
|
||
displacement = displacement_vaddr;
|
||
|
||
break;
|
||
}
|
||
|
||
/* Now compare BUF and BUF2 with optional DISPLACEMENT. */
|
||
|
||
for (i = 0;
|
||
i < phdrs_target->size () / sizeof (Elf64_External_Phdr);
|
||
i++)
|
||
{
|
||
Elf64_External_Phdr *phdrp;
|
||
Elf64_External_Phdr *phdr2p;
|
||
gdb_byte *buf_vaddr_p, *buf_paddr_p;
|
||
CORE_ADDR vaddr, paddr;
|
||
asection *plt2_asect;
|
||
|
||
phdrp = &((Elf64_External_Phdr *) phdrs_target->data ())[i];
|
||
buf_vaddr_p = (gdb_byte *) &phdrp->p_vaddr;
|
||
buf_paddr_p = (gdb_byte *) &phdrp->p_paddr;
|
||
phdr2p = &((Elf64_External_Phdr *) phdrs_binary->data ())[i];
|
||
|
||
/* PT_GNU_STACK is an exception by being never relocated by
|
||
prelink as its addresses are always zero. */
|
||
|
||
if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
|
||
continue;
|
||
|
||
/* Check also other adjustment combinations - PR 11786. */
|
||
|
||
vaddr = extract_unsigned_integer (buf_vaddr_p, 8,
|
||
byte_order);
|
||
vaddr -= displacement;
|
||
store_unsigned_integer (buf_vaddr_p, 8, byte_order, vaddr);
|
||
|
||
paddr = extract_unsigned_integer (buf_paddr_p, 8,
|
||
byte_order);
|
||
paddr -= displacement;
|
||
store_unsigned_integer (buf_paddr_p, 8, byte_order, paddr);
|
||
|
||
if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
|
||
continue;
|
||
|
||
/* Strip modifies the flags and alignment of PT_GNU_RELRO.
|
||
CentOS-5 has problems with filesz, memsz as well.
|
||
Strip also modifies memsz of PT_TLS.
|
||
See PR 11786. */
|
||
if (phdr2[i].p_type == PT_GNU_RELRO
|
||
|| phdr2[i].p_type == PT_TLS)
|
||
{
|
||
Elf64_External_Phdr tmp_phdr = *phdrp;
|
||
Elf64_External_Phdr tmp_phdr2 = *phdr2p;
|
||
|
||
memset (tmp_phdr.p_filesz, 0, 8);
|
||
memset (tmp_phdr.p_memsz, 0, 8);
|
||
memset (tmp_phdr.p_flags, 0, 4);
|
||
memset (tmp_phdr.p_align, 0, 8);
|
||
memset (tmp_phdr2.p_filesz, 0, 8);
|
||
memset (tmp_phdr2.p_memsz, 0, 8);
|
||
memset (tmp_phdr2.p_flags, 0, 4);
|
||
memset (tmp_phdr2.p_align, 0, 8);
|
||
|
||
if (memcmp (&tmp_phdr, &tmp_phdr2, sizeof (tmp_phdr))
|
||
== 0)
|
||
continue;
|
||
}
|
||
|
||
/* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
|
||
plt2_asect
|
||
= bfd_get_section_by_name (current_program_space->exec_bfd (),
|
||
".plt");
|
||
if (plt2_asect)
|
||
{
|
||
int content2;
|
||
gdb_byte *buf_filesz_p = (gdb_byte *) &phdrp->p_filesz;
|
||
CORE_ADDR filesz;
|
||
|
||
content2 = (bfd_section_flags (plt2_asect)
|
||
& SEC_HAS_CONTENTS) != 0;
|
||
|
||
filesz = extract_unsigned_integer (buf_filesz_p, 8,
|
||
byte_order);
|
||
|
||
/* PLT2_ASECT is from on-disk file (current
|
||
exec_bfd) while FILESZ is from the in-memory
|
||
image. */
|
||
if (content2)
|
||
filesz += bfd_section_size (plt2_asect);
|
||
else
|
||
filesz -= bfd_section_size (plt2_asect);
|
||
|
||
store_unsigned_integer (buf_filesz_p, 8, byte_order,
|
||
filesz);
|
||
|
||
if (memcmp (phdrp, phdr2p, sizeof (*phdrp)) == 0)
|
||
continue;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
}
|
||
else
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
if (info_verbose)
|
||
{
|
||
/* It can be printed repeatedly as there is no easy way to check
|
||
the executable symbols/file has been already relocated to
|
||
displacement. */
|
||
|
||
gdb_printf (_("Using PIE (Position Independent Executable) "
|
||
"displacement %s for \"%s\".\n"),
|
||
paddress (target_gdbarch (), exec_displacement),
|
||
bfd_get_filename (current_program_space->exec_bfd ()));
|
||
}
|
||
|
||
*displacementp = exec_displacement;
|
||
return 1;
|
||
}
|
||
|
||
/* Relocate the main executable. This function should be called upon
|
||
stopping the inferior process at the entry point to the program.
|
||
The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
|
||
different, the main executable is relocated by the proper amount. */
|
||
|
||
static void
|
||
svr4_relocate_main_executable (void)
|
||
{
|
||
CORE_ADDR displacement;
|
||
|
||
/* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
|
||
probably contains the offsets computed using the PIE displacement
|
||
from the previous run, which of course are irrelevant for this run.
|
||
So we need to determine the new PIE displacement and recompute the
|
||
section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
|
||
already contains pre-computed offsets.
|
||
|
||
If we cannot compute the PIE displacement, either:
|
||
|
||
- The executable is not PIE.
|
||
|
||
- SYMFILE_OBJFILE does not match the executable started in the target.
|
||
This can happen for main executable symbols loaded at the host while
|
||
`ld.so --ld-args main-executable' is loaded in the target.
|
||
|
||
Then we leave the section offsets untouched and use them as is for
|
||
this run. Either:
|
||
|
||
- These section offsets were properly reset earlier, and thus
|
||
already contain the correct values. This can happen for instance
|
||
when reconnecting via the remote protocol to a target that supports
|
||
the `qOffsets' packet.
|
||
|
||
- The section offsets were not reset earlier, and the best we can
|
||
hope is that the old offsets are still applicable to the new run. */
|
||
|
||
if (! svr4_exec_displacement (&displacement))
|
||
return;
|
||
|
||
/* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
|
||
addresses. */
|
||
|
||
objfile *objf = current_program_space->symfile_object_file;
|
||
if (objf)
|
||
{
|
||
section_offsets new_offsets (objf->section_offsets.size (),
|
||
displacement);
|
||
objfile_relocate (objf, new_offsets);
|
||
}
|
||
else if (current_program_space->exec_bfd ())
|
||
{
|
||
asection *asect;
|
||
|
||
bfd *exec_bfd = current_program_space->exec_bfd ();
|
||
for (asect = exec_bfd->sections; asect != NULL; asect = asect->next)
|
||
exec_set_section_address (bfd_get_filename (exec_bfd), asect->index,
|
||
bfd_section_vma (asect) + displacement);
|
||
}
|
||
}
|
||
|
||
/* Implement the "create_inferior_hook" target_solib_ops method.
|
||
|
||
For SVR4 executables, this first instruction is either the first
|
||
instruction in the dynamic linker (for dynamically linked
|
||
executables) or the instruction at "start" for statically linked
|
||
executables. For dynamically linked executables, the system
|
||
first exec's /lib/libc.so.N, which contains the dynamic linker,
|
||
and starts it running. The dynamic linker maps in any needed
|
||
shared libraries, maps in the actual user executable, and then
|
||
jumps to "start" in the user executable.
|
||
|
||
We can arrange to cooperate with the dynamic linker to discover the
|
||
names of shared libraries that are dynamically linked, and the base
|
||
addresses to which they are linked.
|
||
|
||
This function is responsible for discovering those names and
|
||
addresses, and saving sufficient information about them to allow
|
||
their symbols to be read at a later time. */
|
||
|
||
static void
|
||
svr4_solib_create_inferior_hook (int from_tty)
|
||
{
|
||
struct svr4_info *info;
|
||
|
||
info = get_svr4_info (current_program_space);
|
||
|
||
/* Clear the probes-based interface's state. */
|
||
free_probes_table (info);
|
||
free_solib_list (info);
|
||
|
||
/* Relocate the main executable if necessary. */
|
||
svr4_relocate_main_executable ();
|
||
|
||
/* No point setting a breakpoint in the dynamic linker if we can't
|
||
hit it (e.g., a core file, or a trace file). */
|
||
if (!target_has_execution ())
|
||
return;
|
||
|
||
if (!svr4_have_link_map_offsets ())
|
||
return;
|
||
|
||
if (!enable_break (info, from_tty))
|
||
return;
|
||
}
|
||
|
||
static void
|
||
svr4_clear_solib (void)
|
||
{
|
||
struct svr4_info *info;
|
||
|
||
info = get_svr4_info (current_program_space);
|
||
info->debug_base = 0;
|
||
info->debug_loader_offset_p = 0;
|
||
info->debug_loader_offset = 0;
|
||
xfree (info->debug_loader_name);
|
||
info->debug_loader_name = NULL;
|
||
}
|
||
|
||
/* Clear any bits of ADDR that wouldn't fit in a target-format
|
||
data pointer. "Data pointer" here refers to whatever sort of
|
||
address the dynamic linker uses to manage its sections. At the
|
||
moment, we don't support shared libraries on any processors where
|
||
code and data pointers are different sizes.
|
||
|
||
This isn't really the right solution. What we really need here is
|
||
a way to do arithmetic on CORE_ADDR values that respects the
|
||
natural pointer/address correspondence. (For example, on the MIPS,
|
||
converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
|
||
sign-extend the value. There, simply truncating the bits above
|
||
gdbarch_ptr_bit, as we do below, is no good.) This should probably
|
||
be a new gdbarch method or something. */
|
||
static CORE_ADDR
|
||
svr4_truncate_ptr (CORE_ADDR addr)
|
||
{
|
||
if (gdbarch_ptr_bit (target_gdbarch ()) == sizeof (CORE_ADDR) * 8)
|
||
/* We don't need to truncate anything, and the bit twiddling below
|
||
will fail due to overflow problems. */
|
||
return addr;
|
||
else
|
||
return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (target_gdbarch ())) - 1);
|
||
}
|
||
|
||
|
||
static void
|
||
svr4_relocate_section_addresses (struct so_list *so,
|
||
struct target_section *sec)
|
||
{
|
||
bfd *abfd = sec->the_bfd_section->owner;
|
||
|
||
sec->addr = svr4_truncate_ptr (sec->addr + lm_addr_check (so, abfd));
|
||
sec->endaddr = svr4_truncate_ptr (sec->endaddr + lm_addr_check (so, abfd));
|
||
}
|
||
|
||
|
||
/* Architecture-specific operations. */
|
||
|
||
/* Per-architecture data key. */
|
||
static struct gdbarch_data *solib_svr4_data;
|
||
|
||
struct solib_svr4_ops
|
||
{
|
||
/* Return a description of the layout of `struct link_map'. */
|
||
struct link_map_offsets *(*fetch_link_map_offsets)(void);
|
||
};
|
||
|
||
/* Return a default for the architecture-specific operations. */
|
||
|
||
static void *
|
||
solib_svr4_init (struct obstack *obstack)
|
||
{
|
||
struct solib_svr4_ops *ops;
|
||
|
||
ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops);
|
||
ops->fetch_link_map_offsets = NULL;
|
||
return ops;
|
||
}
|
||
|
||
/* Set the architecture-specific `struct link_map_offsets' fetcher for
|
||
GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
|
||
|
||
void
|
||
set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
|
||
struct link_map_offsets *(*flmo) (void))
|
||
{
|
||
struct solib_svr4_ops *ops
|
||
= (struct solib_svr4_ops *) gdbarch_data (gdbarch, solib_svr4_data);
|
||
|
||
ops->fetch_link_map_offsets = flmo;
|
||
|
||
set_solib_ops (gdbarch, &svr4_so_ops);
|
||
set_gdbarch_iterate_over_objfiles_in_search_order
|
||
(gdbarch, svr4_iterate_over_objfiles_in_search_order);
|
||
}
|
||
|
||
/* Fetch a link_map_offsets structure using the architecture-specific
|
||
`struct link_map_offsets' fetcher. */
|
||
|
||
static struct link_map_offsets *
|
||
svr4_fetch_link_map_offsets (void)
|
||
{
|
||
struct solib_svr4_ops *ops
|
||
= (struct solib_svr4_ops *) gdbarch_data (target_gdbarch (),
|
||
solib_svr4_data);
|
||
|
||
gdb_assert (ops->fetch_link_map_offsets);
|
||
return ops->fetch_link_map_offsets ();
|
||
}
|
||
|
||
/* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
|
||
|
||
static int
|
||
svr4_have_link_map_offsets (void)
|
||
{
|
||
struct solib_svr4_ops *ops
|
||
= (struct solib_svr4_ops *) gdbarch_data (target_gdbarch (),
|
||
solib_svr4_data);
|
||
|
||
return (ops->fetch_link_map_offsets != NULL);
|
||
}
|
||
|
||
|
||
/* Most OS'es that have SVR4-style ELF dynamic libraries define a
|
||
`struct r_debug' and a `struct link_map' that are binary compatible
|
||
with the original SVR4 implementation. */
|
||
|
||
/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
|
||
for an ILP32 SVR4 system. */
|
||
|
||
struct link_map_offsets *
|
||
svr4_ilp32_fetch_link_map_offsets (void)
|
||
{
|
||
static struct link_map_offsets lmo;
|
||
static struct link_map_offsets *lmp = NULL;
|
||
|
||
if (lmp == NULL)
|
||
{
|
||
lmp = &lmo;
|
||
|
||
lmo.r_version_offset = 0;
|
||
lmo.r_version_size = 4;
|
||
lmo.r_map_offset = 4;
|
||
lmo.r_brk_offset = 8;
|
||
lmo.r_ldsomap_offset = 20;
|
||
|
||
/* Everything we need is in the first 20 bytes. */
|
||
lmo.link_map_size = 20;
|
||
lmo.l_addr_offset = 0;
|
||
lmo.l_name_offset = 4;
|
||
lmo.l_ld_offset = 8;
|
||
lmo.l_next_offset = 12;
|
||
lmo.l_prev_offset = 16;
|
||
}
|
||
|
||
return lmp;
|
||
}
|
||
|
||
/* Fetch (and possibly build) an appropriate `struct link_map_offsets'
|
||
for an LP64 SVR4 system. */
|
||
|
||
struct link_map_offsets *
|
||
svr4_lp64_fetch_link_map_offsets (void)
|
||
{
|
||
static struct link_map_offsets lmo;
|
||
static struct link_map_offsets *lmp = NULL;
|
||
|
||
if (lmp == NULL)
|
||
{
|
||
lmp = &lmo;
|
||
|
||
lmo.r_version_offset = 0;
|
||
lmo.r_version_size = 4;
|
||
lmo.r_map_offset = 8;
|
||
lmo.r_brk_offset = 16;
|
||
lmo.r_ldsomap_offset = 40;
|
||
|
||
/* Everything we need is in the first 40 bytes. */
|
||
lmo.link_map_size = 40;
|
||
lmo.l_addr_offset = 0;
|
||
lmo.l_name_offset = 8;
|
||
lmo.l_ld_offset = 16;
|
||
lmo.l_next_offset = 24;
|
||
lmo.l_prev_offset = 32;
|
||
}
|
||
|
||
return lmp;
|
||
}
|
||
|
||
|
||
struct target_so_ops svr4_so_ops;
|
||
|
||
/* Search order for ELF DSOs linked with -Bsymbolic. Those DSOs have a
|
||
different rule for symbol lookup. The lookup begins here in the DSO, not in
|
||
the main executable. */
|
||
|
||
static void
|
||
svr4_iterate_over_objfiles_in_search_order
|
||
(struct gdbarch *gdbarch,
|
||
iterate_over_objfiles_in_search_order_cb_ftype *cb,
|
||
void *cb_data, struct objfile *current_objfile)
|
||
{
|
||
bool checked_current_objfile = false;
|
||
if (current_objfile != nullptr)
|
||
{
|
||
bfd *abfd;
|
||
|
||
if (current_objfile->separate_debug_objfile_backlink != nullptr)
|
||
current_objfile = current_objfile->separate_debug_objfile_backlink;
|
||
|
||
if (current_objfile == current_program_space->symfile_object_file)
|
||
abfd = current_program_space->exec_bfd ();
|
||
else
|
||
abfd = current_objfile->obfd;
|
||
|
||
if (abfd != nullptr
|
||
&& gdb_bfd_scan_elf_dyntag (DT_SYMBOLIC, abfd, nullptr, nullptr) == 1)
|
||
{
|
||
checked_current_objfile = true;
|
||
if (cb (current_objfile, cb_data) != 0)
|
||
return;
|
||
}
|
||
}
|
||
|
||
for (objfile *objfile : current_program_space->objfiles ())
|
||
{
|
||
if (checked_current_objfile && objfile == current_objfile)
|
||
continue;
|
||
if (cb (objfile, cb_data) != 0)
|
||
return;
|
||
}
|
||
}
|
||
|
||
void _initialize_svr4_solib ();
|
||
void
|
||
_initialize_svr4_solib ()
|
||
{
|
||
solib_svr4_data = gdbarch_data_register_pre_init (solib_svr4_init);
|
||
|
||
svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses;
|
||
svr4_so_ops.free_so = svr4_free_so;
|
||
svr4_so_ops.clear_so = svr4_clear_so;
|
||
svr4_so_ops.clear_solib = svr4_clear_solib;
|
||
svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook;
|
||
svr4_so_ops.current_sos = svr4_current_sos;
|
||
svr4_so_ops.open_symbol_file_object = open_symbol_file_object;
|
||
svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code;
|
||
svr4_so_ops.bfd_open = solib_bfd_open;
|
||
svr4_so_ops.same = svr4_same;
|
||
svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core;
|
||
svr4_so_ops.update_breakpoints = svr4_update_solib_event_breakpoints;
|
||
svr4_so_ops.handle_event = svr4_handle_solib_event;
|
||
|
||
gdb::observers::free_objfile.attach (svr4_free_objfile_observer,
|
||
"solib-svr4");
|
||
}
|